Biology Tools
Browse all available biology tools.
Available tools
- 2021 CKD-EPI eGFR Estimate adult glomerular filtration rate with the 2021 race-free CKD-EPI creatinine equation. The result is normalized to 1.73 square metres of body surface area and is an estimate, not a measured GFR.
- 260/230 Ratio Calculate the A260/A230 purity ratio used to detect organic compounds and salts carried over from extraction.
- 260/280 Ratio Calculate the A260/A280 purity ratio used to assess nucleic acid contamination by protein.
- 3' GC Clamp Count Count guanine and cytosine bases among the last three nucleotides of a primer sequence.
- 305-Day Milk Correction Project a lactation yield to a 305-day basis as current yield divided by days in milk times three hundred five.
- A-a Gradient Compute the alveolar-arterial oxygen gradient as fiO2 x (patm - 47) - paco2 / 0.8 - pao2.
- A-a Gradient Sea Level Compute the sea level alveolar-arterial oxygen gradient as fiO2 x (760 - 47) - paco2 / 0.8 - pao2.
- a/A Ratio Compute the arterial-to-alveolar oxygen ratio as PaO2 divided by the alveolar oxygen tension from the simplified alveolar gas equation.
- Absolute Refractory Check Check whether a neuron is inside its absolute refractory period by comparing elapsed time since the last spike against the absolute refractory window.
- Absolute Reticulocytes Compute absolute reticulocyte count from reticulocyte percentage and RBC count.
- Accumulation Slope Segment Compute the species accumulation rate for one survey segment as new species divided by units of sampling effort.
- ACE Bias Corrected Estimate abundance-based species richness with ACE using the species observed at most ten times, their total individuals, singleton count, and the rare-frequency moment sum i(i-1)f_i. ACE is undefined when every rare individual is a singleton.
- ACE Proxy Estimator Compute the singleton-doubleton proxy Sobs + F1 squared divided by 2 F2, substituting one when F2 is zero. This is not the full abundance-based coverage estimator, which requires the rare-species frequency distribution.
- Additive Relationship Compute the additive relationship contribution of one common ancestor path as the number of paths times 0.5 raised to the generation distance.
- Additive Variance Component Derive the additive genetic variance by subtracting dominance and epistatic components from the total genetic variance.
- Airway Resistance Compute airway resistance as peak pressure minus plateau pressure divided by inspiratory flow.
- Allele Count Total Count total allele copies at a diploid locus as twice the number of individuals.
- Allele Freq From Counts Compute allele A frequency p = (2*AA + AB) / (2*(AA + AB + BB)) from genotype counts.
- Allele Frequency p Estimate dominant allele frequency p from genotype counts using p = (2*AA + Aa) / (2*total).
- Alveolar Gas Equation Compute the ideal alveolar oxygen pressure PAO2 = FiO2 x (Patm - PH2O) - PaCO2 / R, with water vapour pressure defaulting to 47 mmHg at body temperature and respiratory quotient R defaulting to 0.8.
- Alveolar Ventilation L/min Compute alveolar ventilation in litres per minute as (tidal volume - dead space) x respiratory rate / 1000.
- Amplicon Length Calculate the amplicon length in base pairs spanned by forward and reverse primer positions.
- ANC Calculator Compute absolute neutrophil count from white blood cell count and neutrophil percentage.
- Anion Gap Compute the serum anion gap from sodium, chloride, and bicarbonate.
- Annealing Temp Rule Estimate the PCR annealing temperature as the lower primer melting temperature minus five degrees.
- Anthocyanin Content Compute anthocyanin content in micrograms per gram of dry mass as the corrected absorbance divided by the dry mass times an extinction scale factor that defaults to one hundred; apply any baseline correction to the absorbance upstream before passing it in.
- Apoptosis % Calculate the apoptosis percentage from apoptotic and total cell counts.
- Apoptotic Index Compute the apoptotic index as the ratio of apoptotic cells to mitotic cells.
- Apparent Vd Estimate volume of distribution as the systemically available dose (administered dose times bioavailability) divided by plasma concentration.
- APTT Ratio Compute the activated partial thromboplastin time ratio as the patient APTT divided by the control APTT.
- ARC From Percent Compute the absolute reticulocyte count in thousands per microlitre as the reticulocyte percent times the RBC count in millions per microlitre times ten.
- AT Content Calculator Calculate the percentage of A and T bases in a DNA sequence.
- Average Daily Gain Compute average daily gain as (final weight - initial weight) / days elapsed in kilograms per day; the result is signed, so weight loss yields a negative value.
- Backfat Class Lookup Classify an ultrasound backfat measurement in millimetres as lean, optimal, or over-finished.
- Band Intensity Ratio Normalise a western blot target band by dividing its densitometry intensity by the loading control intensity of the same lane.
- Bark Density Compute bark density in grams per cubic centimetre as oven-dry bark mass divided by bark volume.
- Bark Thickness Percent Express bark thickness as a percentage of trunk diameter at breast height from millimetres and centimetres.
- Berger-Parker Dominance Compute the Berger Parker dominance index as the most abundant count over total individuals.
- Bioavailability % Compute oral bioavailability as a percentage from AUC and dose comparisons.
- Bioequivalence Ratio Express bioequivalence as the test product area under the curve as a percentage of the reference product area under the curve.
- Biological Half-Life Compute the elimination half-life from volume of distribution and clearance.
- Bleeding Time Category Classify a bleeding time in minutes up to 30 as normal (<= 7), borderline (<= 15), or prolonged.
- Body Length Weight Estimate cattle weight in kilograms from body length and chest girth with the same-family length formula.
- Bohr Dead Space Compute physiologic dead space with the Bohr equation: Vd = Vt x (PaCO2 - EtCO2) / PaCO2.
- Bohr Effect Shift Compute the Bohr effect shift of hemoglobin oxygen affinity as shiftLogP50 = phiBohrCoefficient x (pH2 - pH1), where phi is the signed Bohr coefficient, negative by convention and defaulting to -0.48 for human whole blood.
- Bone Percentage Compute the bone mass percentage of a dressed carcass weight.
- Bootstrap Richness Proxy Compute the limited richness proxy Sobs + singletons divided by sample count. A full bootstrap richness estimator requires each species' observed incidence frequency.
- BP Category Lookup Classify a blood pressure reading as normal, elevated, stage-1 or stage-2; systolic must exceed diastolic.
- Bradford Protein Conc Convert a Bradford assay A595 reading into protein concentration using the slope of the standard curve.
- Brain Allometry Slope Predict brain mass from body mass with the allometric power law predictedBrainMassG = 10^(intercept + slope x log10(bodyMassG)); defaults use intercept -1.0 g and slope 0.75 for the vertebrate brain-body scaling line.
- Brain-Body Ratio Compute the gross brain-body mass ratio as brain mass in grams divided by body mass in kilograms.
- Bray-Curtis Dissimilarity Quantify compositional dissimilarity between two communities over two species with the Bray-Curtis index.
- BrdU Incorporation Rate Compute the percentage of BrdU positive cells relative to the total counted cell population.
- BrdU Labeling Index Compute the BrdU labeling index as the percentage of BrdU-labeled nuclei.
- Breeding Value EBV Estimate an individual breeding value as heritability times the signed phenotype deviation from the population mean.
- Brillouin Index Compute the Brillouin diversity index HB = (ln(N!) - sum(ln(ni!))) / N from three species counts using loop-based log factorials for communities up to 10000 individuals.
- Broad-Sense Heritability Compute broad-sense heritability as the ratio of total genotypic variance to phenotypic variance.
- BSA DuBois Estimate body surface area with the DuBois formula.
- BSA Mosteller Estimate body surface area with the Mosteller formula.
- BUN Creatinine Ratio Compute the blood urea nitrogen to serum creatinine ratio.
- Canopy Bulk Density Compute canopy bulk density in kilograms per cubic metre as the canopy fuel mass divided by the canopy volume.
- Canopy Cover % Compute canopy cover as canopy area divided by total plot area times 100.
- Canopy Height Difference Derive canopy height by subtracting the ground elevation from the maximum surface elevation of a canopy height model.
- Carcass Fat % Compute the dissectible fat mass percentage of a dressed carcass weight.
- Carcass Yield % Compute dressing yield as the carcass weight percentage of the live weight.
- Cardiac Index Compute cardiac index as cardiac output divided by body surface area.
- Cardiac Output L/min Compute cardiac output from heart rate and stroke volume.
- Cardiac Power Output Compute cardiac power output from cardiac output and mean arterial pressure.
- Carotenoid Content Estimate total carotenoid content in micrograms per gram of leaf fresh mass as the absorbance at 480 nanometers times four divided by the fresh mass, following the documented Arnon-proxy extinction scaling.
- Carrier Frequency Estimate heterozygous carrier frequency 2q(1-q) from the incidence q^2 of a recessive disease.
- Carrying Capacity Check Check whether a population exceeds its habitat carrying capacity.
- Cell Concentration From Dilution Recover the original cell concentration by scaling a counted dilution.
- Cell Diameter From Area Derive the diameter of a spherical cell from its surface area in square micrometers.
- Cell Dilution C1V1=C2V2 Solve C1V1=C2V2 for the stock volume needed to reach a target concentration.
- Cell Surface Area Sphere Compute the surface area of a spherical cell from its radius in micrometers.
- Cell Viability % Calculate the viability percentage from viable and total cell counts.
- Cell Volume Sphere Compute the volume of a spherical cell in femtoliters, where one cubic micrometer equals one femtoliter.
- CFSE Dilution Factor Estimate cell division count from CFSE fluorescence dilution using the base two logarithm of the initial over current intensity.
- CFSE MFI Halving Infer the number of CFSE fluorescence halvings, and hence cell generations, from parent and current mean fluorescence intensities.
- CFU Per mL Estimate colony-forming units per milliliter from a plate colony count, dilution factor, and plating volume.
- CFU Total Estimate Estimate the total colony-forming units in a culture from concentration and volume.
- Chao1 Bias Corrected Compute the documented bias-corrected Chao1 estimate as observed species plus singletons times singletons minus one divided by two times doubletons plus one.
- Chao1 Estimator Estimate total species richness from singletons and doubletons in a single sample using the Chao1 estimator.
- Chao2 Estimator Estimate total species richness from incidence data across samples using the Chao2 estimator.
- Cheng-Prusoff IC50 Convert an observed IC50 from a competitive binding assay to Ki with the Cheng-Prusoff equation: Ki = IC50 / (1 + [L]/Kd). The relationship assumes equilibrium competition at a single binding site without substantial tracer depletion.
- Chest Girth Weight Estimate cattle weight in kilograms from the chest girth with the documented cubic approximation.
- Chl a/b Ratio Compute the chlorophyll a to chlorophyll b ratio from pigment concentrations in micrograms per milliliter.
- Classic Shunt Equation Compute the physiologic shunt fraction as the classic shunt equation Qs/Qt = (CcO2 - CaO2) / (CcO2 - CvO2).
- Clearance Rate Compute drug clearance from an administered dose and the plasma AUC.
- Clotting Time Category Flag whether a clotting time between 30 and 600 seconds falls inside the normal range of 90 to 180 seconds inclusive.
- CMS Percent Compute cell membrane stability as a percentage by comparing the control conductivity ratio to the treated conductivity ratio, control divided by treated times one hundred, clamped to the range zero through one hundred.
- Coancestry Coefficient Compute the coancestry or kinship phi of two individuals as half of their additive relationship coefficient.
- Cockcroft-Gault CrCl Estimate creatinine clearance with the Cockcroft-Gault equation.
- Codon Count Count how many complete three-base codons fit in a nucleotide sequence.
- Codon Frequency Calculate the frequency of a codon within the reading frame of a DNA sequence.
- Codon Usage Bias Frequency Compute the relative usage frequency of a codon among codons for the same amino acid.
- Conduction Velocity Estimate myelinated axon conduction velocity with the documented linear factor of about 6 metres per second per micrometre of fibre diameter.
- Confluence % Compute the percentage of a culture vessel surface covered by cells from occupied and total flask areas.
- Corrected Calcium Adjust measured calcium for hypoalbuminemia with the 0.8 correction.
- Corrected Retic Percent Correct the reticulocyte percent for anemia by multiplying by the patient to normal hematocrit ratio with a reference normal hematocrit of 45 percent.
- Corrected Sodium Correct measured serum sodium for hyperglycemia with the 1.6 per 100 mg/dL rule.
- Creatinine-Based Clearance Compute renal creatinine clearance as urine volume times urine creatinine divided by plasma creatinine and the collection time in minutes.
- Crop Growth Rate Compute crop growth rate in grams per square metre of ground per day as standing dry mass gain divided by ground area times elapsed days.
- CWSI Calculator Compute the crop water stress index as (canopy temperature - wet reference temperature) / (dry reference temperature - wet reference temperature), clamped to the range zero through one.
- Dairy BCS Ratio Mapping Map a precomputed body-condition ratio onto a one-to-five score with round(ratio times five), clamped to the scale. This is a heuristic mapping, not a substitute for visual and palpation scoring.
- Delta CT Calculate the signed delta CT value by subtracting the reference Ct from the target Ct.
- Delta Delta CT Calculate the delta delta CT value by subtracting the control delta CT from the treated delta CT.
- Differential Absolute Neutrophil Compute the absolute neutrophil count from the neutrophil differential percentage and the total white blood cell count.
- Dihybrid Ratio Report the classic 9:3:3:1 phenotypic fractions of an AaBb x AaBb dihybrid cross.
- DNA Complement Map each DNA base to its complement, pairing A with T and G with C.
- DNA Conc From A260 Convert an A260 absorbance reading into double-stranded DNA concentration using the 50 ng/µL per absorbance unit factor.
- DNA Copy Number Calculate the number of DNA molecules from mass in nanograms and length in base pairs.
- Dominance Variance Share Express the dominance variance component as a percentage of the total genetic variance.
- Donnan Potential Compute the equilibrium potential at 25 °C from the inside-to-outside concentration ratio. The base-10 Nernst factor is 59.16 mV per tenfold concentration gradient and is divided by ion valence.
- Doubling Time (PDT) Calculate population doubling time as elapsed hours times ln(2), divided by ln(final count / initial count).
- Dressing Percentage Compute dressing percentage as the hot carcass weight percentage of the shrunk live weight.
- Drift Variance Compute the expected one-generation variance in allele frequency under diploid Wright-Fisher drift: p × (1 - p) / (2Ne), where Ne is the effective number of breeding individuals.
- Drought Tolerance Index Compute the drought tolerance index as stressed yield divided by control yield times one hundred.
- Dynamic Compliance Compute dynamic respiratory compliance as tidal volume divided by peak inspiratory pressure minus PEEP.
- eAG From A1c Estimate average glucose in mg/dL from hemoglobin A1c with the documented ADAG regression 28.7 x A1c - 46.7.
- EBV Accuracy Convert an estimated breeding value reliability into the accuracy correlation as the square root of the reliability.
- EC50 From Hill Estimate the half-maximal effective concentration by inverting the Hill equation.
- Ecological Doubling Time Compute the doubling time of a population growing exponentially.
- Effective Population Size Compute the sex-ratio effective population size ne = (4 * males * females) / (males + females).
- Ejection Fraction % Compute ejection fraction as a percentage of end-diastolic volume.
- Elastance Calculator Compute respiratory elastance as transpulmonary pressure divided by tidal volume in liters.
- Elastic WOB Compute elastic work of breathing per breath as one half times elastance times tidal volume squared, converted to joules with 0.0981 J per cmH2O-L.
- Electrolyte Leakage % Compute electrolyte leakage as initial conductivity divided by boiled conductivity times 100, requiring a positive boiled conductivity and an initial conductivity that does not exceed it.
- Elimination Half-Life Compute the first-order elimination half-life as 0.693 times the volume of distribution divided by the clearance.
- ELISA Linear Standard Curve Interpolate an ELISA sample concentration on a linear standard curve as (absorbance − intercept) / slope. This calculation is only appropriate over a validated linear assay range; it is not a four-parameter logistic fit.
- Encephalization Quotient Compare observed brain mass to the expected mass for a body size using primate reference constants: EQ = actualBrainGrams / (11.22 x bodyMassKg^0.76), where 11.22 is the reference intercept in grams and 0.76 the reference exponent.
- Epistasis Variance Share Express the epistatic variance component as a percentage of the total genetic variance.
- EVI Calculator Compute the Enhanced Vegetation Index as 2.5 * (NIR - red) / (NIR + 6 * red - 7.5 * blue + 1) from reflectances between zero and one, rejecting degenerate reflectances that zero the denominator.
- Expected Heterozygosity Compute expected heterozygosity he = 1 - (p^2 + q^2) at a two-allele locus.
- Exponential Growth Project a population with continuous exponential growth.
- Fat Free Mass Compute fat-free body mass in kilograms from body weight and body fat percentage.
- FCR Calculator Compute the feed conversion ratio as feed consumed in kilograms divided by live weight gain in kilograms.
- Ferritin Per Iron Ratio Compute the ratio of ferritin in nanograms per millilitre to serum iron in micrograms per decilitre.
- FEV1/FVC Ratio Compute the FEV1/FVC ratio from forced expiratory volume in one second and forced vital capacity in litres.
- Fick Diffusion Rate Compute the magnitude of steady-state diffusion with Fick's first law. Concentration in mg/mL is equivalent to mg/cm³, and membrane thickness is converted from micrometres to centimetres so the result is in mg/s.
- First Order Jackknife Estimate species richness with the first order jackknife from unique species across incidence samples.
- Fisher Alpha Solve Fisher's log-series diversity parameter from S = alpha × ln(1 + N/alpha). A finite positive solution exists when the observed species count is smaller than the individual count.
- Flow Positive % Compute the percentage of positive events recorded by a flow cytometry run as positive events divided by total events times one hundred.
- Fold Change Compute the fold change between condition and control means with its log2 value.
- Fragment Lengths Count Compute the number of DNA fragments produced by a number of restriction cut sites.
- FST Fixation Index Compute the fixation index fst = (ht - hs) / ht for two populations at a two-allele locus.
- G1 Percentage Compute the percentage of cells in G1 phase relative to the total counted cell population.
- G2 Percentage Compute the percentage of cells in G2 phase from flow cytometry cell cycle counts.
- Gap Fraction % Compute canopy gap fraction as a percentage of sky-visible pixels over total hemispherical image pixels.
- GC Clamp Check Check the GC clamp of a primer by counting guanine and cytosine bases among the last five nucleotides.
- GC Content Calculator Calculate the percentage of G and C bases in a DNA sequence.
- GC Rule Tm Estimate DNA melting temperature with the GC rule for sequences longer than 13 bases.
- GEBV Blend Blend a genomic estimated breeding value and a pedigree estimated breeding value using a weighted average.
- Gene Coordinate Length Calculate gene length from one-based inclusive start and end coordinates: end − start + 1. Inclusive coordinates count both endpoint bases, so a feature whose start and end are equal is one base pair long.
- Genotype Count Check Sum genotype counts and, when a total is supplied, verify the counts reconcile with it.
- Genotype Frequencies Compute expected Hardy-Weinberg genotype frequencies p^2, 2pq, and q^2 from an allele frequency.
- Germination Capacity % Compute germination capacity as the total seeds germinated over the whole assay divided by the seeds sown times one hundred.
- Germination Energy % Compute germination energy as the seeds germinated by the peak day divided by the seeds sown times one hundred; the peak day is the day on which the daily germination count is highest and only counts up to that day are included.
- Germination Percentage Compute germination percentage as germinated seeds divided by seeds sown times one hundred.
- Germination Rate Index Compute the germination rate index over two days as (day one count / 1 + day two count / 2) / seeds sown times 100, expressed in percent per day.
- Gibbs-Donnan Ratio Compute the Gibbs-Donnan ratio as the concentration of permeant ion inside a cell divided by its concentration outside.
- Goldman Equation Compute the Goldman-Hodgkin-Katz steady-state membrane potential at 37 degrees Celsius with the z=+1 cation form for potassium and sodium and inverted terms for chloride: VM = 61.5 x log10((pK x KOut + pNa x NaOut + pCl x ClIn) / (pK x KIn + pNa x NaIn + pCl x ClOut)) mV.
- Hairpin Tm Estimate Estimate primer hairpin stability by searching the sequence against its own reverse complement for the longest internal inverted-repeat stem of three to eight non-overlapping bases and applying the Wallace rule of four degrees per GC pair and two per AT pair.
- Haplotype Frequency Compute haplotype frequency as haplotype count divided by two times the total number of individuals.
- Harrison Beta Compute Harrison's normalized beta-2 turnover for two sites as (S₁ + S₂ - 2C) / (S₁ + S₂), where C is shared richness. The result is zero for identical species sets and one for disjoint sets.
- Harvest Index Compute the harvest index as grain yield divided by total above-ground biomass, which must not exceed the biomass.
- HbA1c Category Lookup Classify a hemoglobin A1c percentage as normal below 5.7 percent, prediabetes below 6.5 percent, or diabetes otherwise.
- Heart Girth Weight Estimate Estimate livestock weight in kilograms from heart girth and body length with the documented heart girth formula.
- Hematocrit % Compute hematocrit percent as the red cell volume divided by the total blood sample volume times 100.
- Hemocytometer Cell Count Convert the average cells per hemocytometer square into cells per milliliter.
- Hemoglobin From Hct Proxy Approximate hemoglobin in g/dL from hematocrit percent with the clinical rule of three: hemoglobin is about one third of hematocrit. This screening proxy can be unreliable when red-cell size or hemoglobinization is abnormal.
- Hill EC50 Fit Check Check a Hill-Langmuir fit by predicting the effect fraction at a concentration from the fitted EC50 and hill slope.
- Hill Number N0 Return the Hill number of order zero, which equals species richness and therefore passes the species count through unchanged.
- Hill Number N1 Convert a natural-log Shannon entropy to the Hill number of order one, the effective number of equally common species, as exp(H).
- Hill Number N2 Convert a Simpson concentration to the Hill number of order two as its reciprocal.
- Hip Height Index Compute the hip height index as a percentage of hip height over heart girth.
- HW Chi-Square Compute a chi-square statistic comparing observed genotype counts against Hardy-Weinberg expectations derived from an allele frequency.
- IC50 Inhibition Conc Estimate the half-maximal inhibitory concentration by inverting the Hill equation.
- Inbreeding Coefficient Compute the inbreeding coefficient f = (he - ho) / he, which may be negative when heterozygote excess occurs.
- INR Ratio Compute the international normalized ratio as (patient PT / mean normal PT)^ISI. Use the International Sensitivity Index assigned to the specific thromboplastin reagent and instrument; the default of one is only appropriate when that is the calibrated ISI.
- Intrinsic WUE Compute intrinsic water use efficiency in micromoles per millimole as the net photosynthesis rate divided by the stomatal conductance.
- Iron Deficiency Indicator Flag iron deficiency when ferritin is below thirty nanograms per millilitre and transferrin saturation is below twenty percent.
- Jaccard Index Compute the Jaccard similarity index between two species counts.
- K-mer Count Count occurrences of an exact k-mer in a DNA sequence with overlapping windows.
- Ki67 Proliferation Index Compute the Ki67 proliferation index as the percentage of Ki67-positive cells.
- Kinship From Path Compute one common-ancestor path contribution to the kinship coefficient as (1/2)^(n₁+n₂+1) × (1+Fₐ), where the path length is the combined generations from both individuals to the ancestor.
- Kleiber BMR Estimate basal metabolic rate across animals with Kleiber's law: BMR = 70 x bodyMass^0.75 kilocalories per day.
- Lab Dilution Series Step Compute one serial dilution step: dilutedConcentration = previousConcentration x transferRatio, where the transfer ratio lies strictly between 0 and 1 and defaults to 0.5 for a two-fold dilution.
- LAI Calculator Compute the leaf area index as total one-sided leaf area divided by the ground surface area it covers.
- LD Coefficient D Compute linkage disequilibrium coefficient D = f(AB) - p(A) * p(B); the signed result may be negative.
- LD R-Squared Compute squared linkage disequilibrium r2 = D^2 / (p(A) * (1 - p(A)) * p(B) * (1 - p(B))).
- LD50 Log-Dose Interpolation Estimate LD50 by linear interpolation of response against log10 dose between an ordered lower point at or below 50% mortality and an ordered higher point at or above 50%. This is a two-point estimate, not a fitted dose-response model.
- LDMC Percent Compute leaf dry matter content as a percentage from oven dry leaf mass over turgid fresh leaf mass.
- Leaf Area Ratio Compute the leaf area ratio in square centimetres of leaf per gram of total plant dry mass.
- Leaf Nitrogen Content Compute leaf nitrogen content in milligrams per gram of leaf dry mass as the nitrogen mass divided by the leaf dry mass.
- Leaf Phosphorus Content Compute leaf phosphorus content in milligrams per gram of leaf dry mass as the phosphorus mass divided by the leaf dry mass.
- Leaf Potassium Content Compute leaf potassium content in milligrams per gram of leaf dry mass as the potassium mass divided by the leaf dry mass.
- Leaf Thickness Mean Compute mean leaf thickness in micrometres as the sum of cross-section thickness measurements divided by the number of slices measured.
- Leaf VPD From RH Compute the leaf vapour pressure deficit in kilopascals from leaf temperature using the Tetens equation for saturation vapour pressure, 0.6108 times e^(17.27 times temperature divided by temperature plus 237.3), scaled by one minus relative humidity over one hundred.
- Leakage Two Step Compute the electrolyte leakage ratio as the initial conductivity divided by the maximum conductivity measured after a second boil; the result is a fraction between zero and one.
- Lincoln Petersen Estimator Estimate population size from two capture sessions with the Lincoln Petersen index.
- LMA Compute leaf mass per area LMA in grams per square metre as leaf dry mass divided by leaf area converted from square centimetres.
- Log Series Alpha Proxy Compute a documented Fisher-lite proxy for the log-series alpha parameter as species count divided by the natural logarithm of total individuals plus one.
- Logistic Growth Value Evaluate the logistic growth model at a given time.
- Lowry Protein Conc Convert a Lowry assay A750 reading into protein concentration by subtracting the blank intercept and dividing by the standard curve slope.
- M Phase Percentage Compute the mitotic fraction of a cell population as a percentage of cells in M phase.
- MAP mmHg Compute mean arterial pressure from systolic and diastolic pressure.
- Marbling Score Lookup Classify a marbling score from the intramuscular fat percentage between one and thirteen percent.
- Margalef Richness Compute the Margalef richness index from species count and total individuals.
- Mastitis Risk Category Classify mastitis risk from the somatic cell count in cells per millilitre.
- MCH Calculator Compute mean corpuscular hemoglobin from hemoglobin and red blood cell count.
- MCHC Calculator Compute mean corpuscular hemoglobin concentration from hemoglobin and hematocrit.
- McIntosh Index Compute the McIntosh diversity index for a three species community from Euclidean distance in species space.
- MCV Calculator Compute mean corpuscular volume from hematocrit and red blood cell count.
- MCV Cross Check Cross check a reported MCV against the computed mean corpuscular volume hematocrit x 10 / RBC and flag agreement within two femtolitres.
- MDRD eGFR Estimate glomerular filtration rate with the four variable MDRD equation.
- Meat To Bone Ratio Compute the carcass meat to bone ratio from lean meat mass and bone mass.
- Membrane Time Constant Compute the passive membrane time constant tau = R x C, converting megaohm-microfarads (seconds) to milliseconds.
- Menhinick Richness Compute the Menhinick richness index as species count divided by the square root of individual count.
- MEPP Amplitude Mean Compute the mean miniature endplate potential amplitude by dividing the summed recorded amplitudes by the number of recorded events.
- MIC/MBC Ratio Compute the ratio of minimum bactericidal concentration to minimum inhibitory concentration; a value of 1 to 4 indicates a bactericidal agent.
- Migration Rate m Compute the migration rate m = migrants per generation / effective population size.
- Migration Speed Compute cell migration speed as distance traveled divided by hours elapsed.
- Mitotic Index % Calculate the mitotic index as the percentage of counted cells in mitosis.
- MOI Calculator Compute the multiplicity of infection as virus particles per target cell.
- Monohybrid Punnett Compute offspring genotype probabilities for a monohybrid cross between two parents.
- Morishita Index Compute Morisita's dispersion index from three quadrat counts as 3 × Σni(ni − 1) divided by N(N − 1).
- Morisita-Horn Counts Quantify overlap between two communities over two species from raw abundance counts with the Morisita-Horn index.
- Morisita-Horn Overlap Compare two communities with the Morisita-Horn similarity coefficient for two categories. Each pair of proportions must sum to one; zero means no shared composition and one means identical composition.
- MSI Percent Compute membrane stability as one minus the ratio of initial to boiled conductivity times 100, requiring a positive boiled conductivity and an initial conductivity that does not exceed it.
- Mutation Rate Compute the mutation rate per generation as new mutations / (population size x generations).
- N Resorption Efficiency Compute nitrogen resorption efficiency in percent as (green leaf N - senesced leaf N) over green leaf N times one hundred.
- N:C Ratio Compute the nucleus-to-cytoplasm ratio from nuclear and cytoplasmic cross-sectional areas.
- Narrow-Sense Heritability Compute narrow-sense heritability as the ratio of additive genetic variance to phenotypic variance.
- NDVI Calculator Compute the Normalized Difference Vegetation Index as (NIR - red) / (NIR + red) from reflectances between zero and one, rejecting dark pixels whose reflectances sum to zero.
- Nearest Neighbor Tm Approx Approximate primer melting temperature with a salt-adjusted nearest-neighbor style formula.
- Necrosis % Calculate the necrosis percentage from necrotic and total cell counts.
- Necrotic Index Compute the percentage of necrotic cells in a counted cell population.
- Nei Genetic Distance Compute Nei's standard genetic distance between two populations at a two-allele locus.
- Nernst Membrane Potential Compute the Nernst equilibrium potential at 37 degrees Celsius in millivolts: EMV = (61.5 / z) x log10(outsideConcentration / insideConcentration), signed positive for outward cation gradient driving force.
- Net Assimilation Rate Compute the simplified net assimilation rate in grams per square metre of leaf per day as dry mass gain divided by average leaf area times elapsed days.
- Net Photosynthesis Rate Compute the net photosynthesis rate in micromoles of carbon dioxide per square metre per second from uptake and leaf area.
- Nitrogen Balance Index Compute grain protein yield per kilogram of applied nitrogen, converting grain protein percentage to a decimal mass fraction before dividing by nitrogen input.
- Nitrogen Nutrition Index Compute the nitrogen nutrition index as actual nitrogen percent divided by critical nitrogen percent; values below one indicate nitrogen dilution.
- NUE Calculator Compute nitrogen use efficiency as grain yield in kilograms divided by nitrogen applied in kilograms.
- O2 Content Blood Compute arterial oxygen content from hemoglobin, saturation, and PaO2.
- O2 Saturation Category Classify peripheral oxygen saturation as hypoxemic (below 90), borderline (90 to below 95) or normal (95 to 100).
- Observed Heterozygosity Compute observed heterozygosity as the fraction of individuals that are heterozygous.
- OD600 To CFU Convert an OD600 absorbance reading to an estimated bacterial density: CFU/mL = OD600 x conversionFactor, using a species-dependent factor that defaults to 1e9 CFU per OD600 unit.
- OI Variant With PEEP Compute an oxygenation index variant as mean airway pressure times the inspired oxygen percentage divided by arterial oxygen tension, without a scaling factor of 100.
- Oligo Extinction Coefficient Estimate the molar extinction coefficient of an oligonucleotide from base composition using nearest-neighbor-less base constants.
- Oligo MW Approx Approximate single-stranded oligonucleotide molecular weight as nucleotide length times the average nucleotide mass of 330 grams per mole.
- Osmotic Potential Van't Hoff Compute osmotic potential in megapascals with the van't Hoff relation as negative i times molal concentration times RT, using R*T = 2.437 MPa*L/mol at 293 K; the van't Hoff factor i defaults to one and may range from one to three.
- Oxygenation Index OI Compute the oxygenation index as mean airway pressure x FiO2 x 100 divided by arterial oxygen tension.
- P Resorption Efficiency Compute phosphorus resorption efficiency in percent as (green leaf P - senesced leaf P) over green leaf P times one hundred.
- P/F Ratio Compute the PaO2/FiO2 ratio used to grade oxygenation impairment; the inspired fraction must lie strictly between 0 and 1.
- Passage Number Compute the current cell passage number from the initial passage and splits.
- PCR Yield Estimate Estimate PCR product yield by compounding the starting copy count once per cycle with an efficiency factor.
- Pedigree F Accumulated Accumulate an inbreeding coefficient as the base coefficient plus the remaining relationship budget times one path contribution.
- Pedigree Inbreeding Loop Compute the path contribution to an offspring inbreeding coefficient for one common ancestor loop.
- PER Calculator Compute the protein efficiency ratio as weight gain in grams divided by protein consumed in grams; the ratio is signed and cannot fall below minus one.
- Phase Mitotic Fraction Compute the fraction of cells positive for a specific mitotic phase marker.
- Phenyl Tyrosine Ratio Compute the phenylalanine to tyrosine concentration ratio in micromoles per litre.
- Phosphorus Nutrition Index Compute the phosphorus nutrition index as actual phosphorus percent divided by critical phosphorus percent; values below one indicate phosphorus dilution.
- Pielou Corrected Compute corrected Pielou evenness as natural Shannon entropy divided by the natural logarithm of the species count, returning exactly zero when entropy is zero.
- Pielou Evenness Compute Pielou evenness J = H / ln(S) from the Shannon index and species count, requiring at least two species.
- Plasma Volume mL Compute the plasma volume as blood volume times one minus the hematocrit fraction.
- Plasmid Copies Per Cell Estimate plasmid copies per cell from plasmid and genomic DNA masses, correcting the mass ratio for their different molecule lengths.
- Plasmid Copy Number Estimate plasmid copies per genome as the concentration ratio scaled by the inverse ratio of molecule lengths.
- Platelet Count Correction Correct a counted platelet number by the dilution factor and the number of counting chambers.
- PNUE Compute photosynthetic nitrogen use efficiency PNUE in micromoles per mole as the net photosynthesis rate divided by the leaf nitrogen per unit area.
- Potassium Nutrition Index Compute the potassium nutrition index as actual potassium percent divided by critical potassium percent; values below one indicate potassium dilution.
- Pressure Potential Compute the pressure (turgor) potential in megapascals as the total water potential minus the osmotic potential; both inputs are signed.
- Primer Concentration nM Convert a single-stranded DNA primer mass concentration in ng per microlitre to nanomolar using an approximate average nucleotide mass of 330 grams per mole.
- Primer Dimer Risk Heuristic primer-dimer screen that aligns one primer with the reverse complement of the other and flags four or more contiguous complementary bases.
- Primer Efficiency From Slope Derive qPCR primer efficiency in percent from the standard curve slope.
- Primer GC Percent Calculate the GC percentage of a primer sequence for clamp design checks.
- Primer Hairpin Risk Heuristic primer-hairpin screen that looks for non-overlapping reverse-complementary stems of at least four bases separated by a loop of at least three bases.
- Primer Length Check Check whether a primer length in bases falls in the optimal 18 to 25 range.
- Probit LD50 Estimate Calculate LD50 from a fitted probit-5 model of the form probit = intercept + slope × log10(dose). Fifty percent response is probit 5, so LD50 = 10^((5 − intercept)/slope).
- Protein Conc From A280 Convert an A280 absorbance reading into protein concentration via the Beer-Lambert mass extinction coefficient in mL/(mg·cm).
- Protein MW From Length Estimate protein molecular weight from residue count using the mean residue mass of 110 daltons.
- PUE Calculator Compute phosphorus use efficiency as yield in kilograms divided by phosphorus applied in kilograms.
- Pulse Pressure Compute pulse pressure as systolic minus diastolic pressure.
- PVR Calculator Compute pulmonary vascular resistance from mean PAP, left atrial pressure, and cardiac output.
- qPCR Copy Number Convert a double-stranded DNA mass in nanograms to molecule count using length and the mean base pair mass of 650 daltons.
- QTc Bazett Correct the QT interval for heart rate with the Bazett formula.
- QTc Fridericia Correct the QT interval for heart rate with the Fridericia formula.
- Quadrat Density Compute organism density as the counted individuals divided by the quadrat area.
- Quantal Content m Estimate the neuromuscular quantal content m as the mean endplate potential amplitude divided by the average miniature endplate potential amplitude.
- Rarefied Richness Estimate rarefied species richness with the documented linear form sTotal x m / n for a subsample of m individuals drawn from n.
- Rarefied Species Curve Point Estimate a rarefied species count with a documented half-saturation form: species total times sample over sample plus half-saturation, where the half-saturation defaults to the total individual count rounded up to its half.
- Ray Proportion Percent Compute the wood ray proportion in percent as the ray pixel area divided by the total cross-section pixel area times one hundred.
- RDW-CV Percent Compute red cell distribution width CV from RBC volume standard deviation and MCV.
- Realized Heritability Compute realized heritability as the signed selection response divided by the selection difference.
- Red Cell Concentration Convert cells counted in a hemocytometer square into a red cell concentration in millions per microliter using countedCells x dilutionFactor / 10.
- Red Cell Mass mL Compute the red cell mass as blood volume times the hematocrit fraction.
- Red Edge NDVI Compute the red edge normalized difference vegetation index as (NIR - red edge) / (NIR + red edge) from reflectances between zero and one, rejecting dark pixels whose reflectances sum to zero.
- Relative Expression Fold Convert a delta delta CT value into a relative fold change using the 2^-ddCt method.
- Relative Fitness Compute relative fitness w = survived offspring / maximum survived offspring in the population.
- Relative Growth Rate Compute plant relative growth rate RGR per day as (ln W2 - ln W1) / elapsed days from dry masses measured at two times.
- Relative Refractory Period Compute the fraction of relative refractory recovery clamped to 0..1 from elapsed time, the absolute refractory duration, and the relative recovery window.
- Resistive WOB Compute resistive work of breathing per breath as resistance times inspiratory flow times tidal volume, converted to joules with 0.0981 J per cmH2O-L.
- Respiratory Rate Check Check whether a respiratory rate in breaths per minute falls within the normal adult range of 12 to 20 inclusive.
- Response To Selection Compute the breeder's equation response to selection as heritability times the signed selection differential.
- Restriction Site Count Count non-overlapping occurrences of a restriction site inside a DNA sequence.
- Reverse Complement Build the reverse complement of a DNA sequence by complementing bases then reversing.
- Ribeye Area Ellipse Compute ribeye area in square centimetres by treating the eye of the longissimus muscle as an ellipse.
- RIN Proxy Estimate an RNA integrity proxy on a one to ten scale from the ratio of 28S to total rRNA peak area.
- RNA Conc From A260 Convert an A260 absorbance reading into RNA concentration using the 40 ng/µL per absorbance unit factor.
- RNA Copy Number Calculate the number of RNA molecules from mass in nanograms and length in nucleotides.
- Root Length Density Compute root length density RLD in centimetres per cubic centimetre of soil as root length divided by soil core volume.
- Root-Shoot Ratio Compute the root-shoot ratio as belowground dry mass divided by aboveground dry mass.
- RPI Corrected Compute the corrected reticulocyte production index as the reticulocyte percent divided by a maturation factor and scaled by the patient to normal hematocrit ratio.
- RPP Compute the rate pressure product from heart rate and systolic pressure.
- Rule Of Three Hct Approximate hematocrit from hemoglobin with the rule of three: each g/dL of hemoglobin contributes about three percent hematocrit.
- RWC Dewpoint Variant Compute relative water content with dew point hygrometer naming as (fresh mass - dry mass) / (turgid mass - dry mass) times 100, requiring the turgid mass to exceed the dry mass and the fresh mass to lie between them.
- RWC Percent Compute relative water content as (fresh mass - dry mass) / (turgid mass - dry mass) times 100, requiring the turgid mass to exceed the dry mass and the fresh mass to lie between them.
- S Phase Fraction Compute the fraction of cells in S phase relative to the total counted cell population.
- SA/V Ratio Compute the surface-area-to-volume ratio of a cube with the given side length, where area is 6 times the square of the side and volume is its cube, giving 6 over the side length.
- Salt Tolerance Index Compute the salt tolerance index as stressed yield divided by control yield times one hundred.
- Salt-Adjusted Tm Estimate DNA melting temperature with a monovalent salt correction from GC fraction and sequence length.
- SCC Linear Score Convert a dairy milk somatic cell count to the standard linear score LS = log2(SCC / 100,000) + 3.
- Schnabel Estimate Estimate population size from a documented two sample Schnabel census.
- Seed Vigor Index Compute the seed vigor index as germination percent times seedling length in centimeters divided by one hundred.
- Seeding Density Compute cell seeding density in cells per square centimeter from a cell count and growth area.
- Seedling Length Vigor Compute the seedling length vigor as the shoot length plus the root length in centimeters.
- Seedling Vigor Index Compute the documented seedling vigor index as germination percent times seedling length in centimeters.
- Selection Coefficient Compute the selection coefficient s = 1 - w from a relative fitness w between 0 and 1.
- Selection Differential Compute the signed selection differential as the mean of selected parents minus the population mean.
- Selection Intensity i Compute the standardized selection intensity as the signed selection difference divided by the phenotypic standard deviation.
- Selectivity Index Compute the ratio of toxic IC50 to therapeutic IC50 for a compound.
- Selectivity Ratio Quantify drug selectivity as the off-target IC50 divided by the on-target IC50, where larger values indicate a more selective compound.
- Self-Dimer Tm Risk Screen a primer for self-dimer risk by aligning it with its reverse complement, finding the longest contiguous complementary run, and flagging runs of at least five bases.
- Sequence Length Count the number of characters in a nucleotide sequence.
- Serial Dilution Biology Compute the endpoint concentration of a serial dilution: finalConcentration = startConcentration x transferRatio^steps, with a strictly fractional transfer ratio and at least one step.
- Shannon Evenness Compute Shannon evenness E = H / ln(S) from the Shannon natural-log diversity index and species count, requiring at least two species.
- Shannon Wiener H Compute the Shannon-Wiener diversity index from up to five species proportions.
- Shunt Fraction % Estimate the physiologic shunt fraction as (CcO2 - CaO2) / (CcO2 - CvO2) x 100, signed.
- Simple Protein pI Estimate protein isoelectric point from acidic and basic residue counts with a linear charge balance model clamped to two through twelve.
- Simpson Evenness Compute Simpson evenness as (1 / D) divided by species count from a Simpson concentration index strictly between zero and one.
- Simpson Index D Compute the Simpson diversity index D for three species counts in a sample.
- Simpson Reciprocal Compute the reciprocal Simpson diversity as one divided by the Simpson concentration.
- Sorensen Index Compute the Sorensen-Dice coefficient of community similarity as 2 times the number of shared species divided by the sum of species counts in both communities.
- SPAD To Chlorophyll Estimate chlorophyll content from a SPAD reading with the documented linear approximation chlorophyll = SPAD value times conversion factor, where the factor defaults to 0.4.
- Species Evenness Pielou Compute Pielou evenness from natural-log Shannon entropy and species count.
- Species Richness Report the number of distinct species observed in a community.
- Specific Growth Rate Calculate the specific growth rate in inverse hours from two counts.
- Specific Leaf Area Compute specific leaf area SLA in square centimetres per gram as one-sided leaf area divided by leaf dry mass.
- Specific Leaf Weight Compute specific leaf weight in grams per square metre as leaf dry mass divided by one-sided leaf area.
- Specific Membrane Capacitance Compute specific membrane capacitance in microfarads per square centimetre as total membrane capacitance divided by membrane area.
- Specific Root Area Compute specific root area SRA in square centimetres per gram as root surface area divided by root dry mass.
- Specific Root Length Compute specific root length SRL in metres per gram as root length divided by root dry mass.
- Static Compliance Compute static respiratory compliance as tidal volume divided by plateau pressure minus PEEP.
- Steady-State Concentration Predict the average plasma concentration at steady state as the infusion rate times bioavailability divided by clearance.
- Stem Wood Density Compute stem wood density in grams per cubic centimetre as oven-dry stem mass divided by stem volume.
- Stomatal Conductance Estimate Estimate stomatal conductance in moles per square metre per second from transpiration and vapour pressure deficit.
- Stomatal Density Compute stomatal density in stomata per square millimetre as the counted stomata divided by the microscopic field area.
- Stomatal Index SI Compute the stomatal index in percent as the stomata count times one hundred over the total of stomata plus epidermal cells.
- Stroke Volume mL Compute stroke volume as end-diastolic volume minus end-systolic volume.
- Stroke Work Calculator Compute left ventricular stroke work from stroke volume and pressure gradient.
- SVR Calculator Compute systemic vascular resistance from MAP, CVP, and cardiac output.
- Synaptic Delay Estimate Estimate total synaptic delay as a fixed base delay plus 0.02 milliseconds per micrometre of transmission distance.
- Therapeutic Index Compute the ratio of the toxic dose TD50 to the effective dose ED50.
- Therapeutic Window Width Measure the width of the therapeutic window as the toxic blood threshold minus the effective blood threshold, both in milligrams per decilitre.
- Three Allele Frequencies Estimate allele frequencies p1, p2 and p3 from three-allele genotype counts using gene counting: pi = (2*nii + sum of heterozygote counts with allele i) / (2*N).
- Tidal Volume Estimate (Radford) Estimate tidal volume using the Radford approximation of 8 mL per kilogram of body weight.
- Total Airway Resistance Compute total airway resistance as the difference between peak inspiratory pressure and pause plateau pressure divided by inspiratory flow.
- Total Blood Volume Estimate Estimate total blood volume from body weight using the documented reference value of 70 millilitres per kilogram.
- Total Compliance Compute total respiratory system compliance as exhaled tidal volume divided by the driving pressure between plateau pressure and total PEEP.
- Total Water Potential Compute the total water potential in megapascals as the sum of the osmotic, pressure, and matric potentials; the matric potential defaults to zero and all inputs are signed.
- Transcribe To RNA Transcribe a DNA sequence to RNA by replacing every thymine with uracil.
- Transcript Length nt Report the length of a transcript in nucleotides.
- Transfection Efficiency % Compute transfection efficiency as the percentage of fluorescent cells.
- Transferrin Saturation % Compute transferrin saturation as serum iron divided by total iron binding capacity times one hundred.
- Transpiration Rate Compute the transpiration rate in millimoles of water per square metre per second from water loss and leaf area.
- Trapezoidal AUC Compute the trapezoidal area under a concentration-time segment as the average of the two concentrations multiplied by the elapsed time interval.
- Trypan Blue Viability % Compute cell viability from trypan blue stained and unstained counts.
- Turgor Pressure Estimate Estimate turgor pressure in megapascals as the total water potential minus the osmotic potential, floored at zero when the cell is flaccid; both potentials are signed and finite.
- Two-Band EVI Compute the two-band Enhanced Vegetation Index as 2.5 * (NIR - red) / (NIR + 2.4 * red + 1) from reflectances between zero and one, rejecting degenerate reflectances that zero the denominator.
- Unmyelinated Conduction Velocity Estimate unmyelinated axon conduction velocity as 0.5 times the square root of fibre diameter in micrometres. The coefficient is empirical and varies with membrane properties and temperature.
- V/Q Mismatch Category Classify a ventilation-perfusion ratio as shunt below 0.3, low up to 0.8, normal below 1.5, and dead-space otherwise.
- V/Q Ratio Compute the ventilation-perfusion ratio as alveolar ventilation divided by pulmonary blood flow.
- VanRaden Genomic Relationship Calculate one off-diagonal genomic relationship using VanRaden's first-method scaling: the cross-product of centered marker genotypes divided by twice the sum of p(1−p) across markers. Negative estimates are possible after centering.
- Vigorous Seedling Index Compute the vigorous seedling index as seedling dry mass in milligrams times the germination percentage divided by one hundred.
- Vital Capacity Compute vital capacity in litres as inspiratory reserve + tidal volume + expiratory reserve.
- Volume Of Distribution Compute the apparent volume of distribution from a dose and plasma concentration.
- VPD Calculator Compute the leaf level vapour pressure deficit in kilopascals as saturation vapour pressure minus actual vapour pressure.
- Wallace Tm Estimate DNA melting temperature with the Wallace rule for sequences up to 14 bases.
- Whittaker Beta Diversity Compute Whittaker beta diversity betaW = gamma / mean alpha richness from two site species counts and their shared count.
- Whittaker Beta Pairwise Compute pairwise Whittaker beta diversity between two sites as the mean site species richness divided by the number of shared species.
- Williams Alpha Compute Williams alpha diversity as the regional species count divided by the number of habitats sampled.
- Withers Height Weight Class Classify livestock frame size as small, medium, or large from the withers height in centimetres.
- Wood Density Compute basic wood density in grams per cubic centimetre as oven-dry mass divided by fresh volume.
- Wood Lactation Curve Predict daily milk yield with the Wood gamma lactation curve over days in milk.
- Wood Specific Gravity Compute wood specific gravity as oven dry mass divided by water displacement volume in cubic centimetres.
- Work Of Breathing Convert a ventilatory pressure into mechanical work per liter of ventilation using the 0.0981 J/L per cmH2O factor.
- Wound Healing Rate Compute wound healing rate as (initial area - current area) / days elapsed.
- WUE Calculator Compute intrinsic water use efficiency as net photosynthesis in micromoles per square metre per second divided by transpiration in millimoles per square metre per second.
- X-Linked Male Frequency Compute the frequency of affected males for an X-linked recessive trait, equal to the recessive allele frequency q under Hardy-Weinberg assumptions.