IntCal Calibration Curve Lookup

Forward independently verified Int Cal curve row lookup/interpolation at calendar BP(year 1950 anchor), not inversion/intercept-band/Bayesian age calibration already implemented; edition/error basis caller supplies. Caller independently establishes sample/context/calibration applicability; not definitive chronology, provenance, taxonomy, disease or human identity.

Description

Radiocarbon calibration relates calendar years to reference radiocarbon ages and uncertainties.

Radiocarbon calibration relates calendar years to reference radiocarbon ages and uncertainties.^[1]

Interpolating that forward curve differs from estimating a calendar-age distribution from a measured radiocarbon date. Use IntCal Calibration Curve Lookup to evaluate the supplied inputs under the model explained below.

When to use IntCal Calibration Curve Lookup

Use IntCal Calibration Curve Lookup to evaluate the supplied inputs under the model explained below. Establish the units, measurement scope and model assumptions before entering values.

How to use IntCal Calibration Curve Lookup and understand its results

Establish the units, measurement scope and model assumptions before entering values.
Enter Caller intcal calendar years bp, Caller intcal c14 ages bp, Caller intcal one sigma years, Query calendar year bp using the field table and validation rules below, then run the tool.
Read Interpolated reference c14 age bp, Interpolated reference one sigma years; interpret the units, signs, ordering and unknown-value placeholders described below.
Correct reported input errors and rerun. Apply successful results according to their specific meanings and check the assumptions before using them in a decision.

Input field	Meaning	Value type	Requirement
callerIntcalCalendarYearsBp	Caller intcal calendar years bp	array of number	Required; constraints below
callerIntcalC14AgesBp	Caller intcal c14 ages bp	array of number	Required; constraints below
callerIntcalOneSigmaYears	Caller intcal one sigma years	array of number	Required; constraints below
queryCalendarYearBp	Query calendar year bp	number	Required; constraints below

Enter at least two strictly increasing finite calendar-year-BP coordinates with aligned radiocarbon-age-BP values and nonnegative one-sigma reference uncertainties, plus an in-range calendar-year query. Independently linearly interpolate age and sigma; exact endpoints are accepted. No IntCal data is installed or downloaded. This forward lookup does not invert a measured radiocarbon age, propagate a laboratory uncertainty or generate a calibrated probability distribution.

referenceC14Age=linearInterpolation(calendarBP,ageBP,query); referenceSigma=linearInterpolation(calendarBP,sigma,query)

Use the field order, units and branch conditions described above.

Output field	Meaning	Value type
interpolatedReferenceC14AgeBp	Interpolated reference c14 age bp	number
interpolatedReferenceOneSigmaYears	Interpolated reference one sigma years	number

json

{
  "input": {
    "callerIntcalCalendarYearsBp": [
      0,
      100,
      200
    ],
    "callerIntcalC14AgesBp": [
      0,
      90,
      210
    ],
    "callerIntcalOneSigmaYears": [
      10,
      20,
      30
    ],
    "queryCalendarYearBp": 150
  },
  "output": {
    "interpolatedReferenceC14AgeBp": 150,
    "interpolatedReferenceOneSigmaYears": 25
  }
}

Limitations and assumptions

Radiocarbon dating requires calibration against known-age material. This tool expects caller-supplied reference coordinates and uncertainties; it contains no IntCal dataset and performs forward interpolation rather than full calendar-age calibration.^[2]

Interpolating that forward curve differs from estimating a calendar-age distribution from a measured radiocarbon date. Apply the exact scope and assumptions explained above.

All listed fields require explicit values. Unexpected fields, incorrect types, nonfinite numbers and sparse arrays fail validation. Domain-specific bounds, alignments and supported tokens are explained above; extremely large inputs or outputs can also be rejected. Input errors differ from successful false results, empty match lists and unknown-evidence placeholders.

Alternative or Complementary methods

Use C14 Age From Activity Calculator for a related task: Radiocarbon activity supports an exponential age under a chosen half-life convention.

Use Uranium-Series Speleothem Age Calculator for a related task: Uranium-series dating relates activity ratios to decay under a closed-system model.

References

IntCal Calibration Curve Lookup — tool.io
Radiocarbon calibration and IntCal reference curves — IntCal Working Group

Similar or alternative tools

C14 Age From Activity Calculator
Radiocarbon activity supports an exponential age under a chosen half-life convention.
Uranium-Series Speleothem Age Calculator
Uranium-series dating relates activity ratios to decay under a closed-system model.