Use this tool to reproduce the documented calculation from laboratory values reported in the required units. It can support verification and education when the applicable patient population and convention are known.

Sodium

A finite measured or assumed value greater than or equal to 5e-324, expressed in mmol/L.

Chloride

A finite measured or assumed value greater than or equal to 5e-324, expressed in mmol/L.

Bicarbonate

A finite measured or assumed value greater than or equal to 5e-324, expressed in mmol/L.

The implementation follows this calculation rule: Compute the serum anion gap from sodium, chloride, and bicarbonate.^[1]

Anion gap

The calculated anion gap in mmol/L.

Calculated laboratory indices are not diagnoses and must not replace clinical interpretation. Assay method, reference interval, age, body size, medications, acute illness, unit conversion, and the population in which an equation was validated can change its meaning. Preserve the input values and units so the result can be audited and recalculated.

Review the original laboratory report, reference interval, trends, and relevant confirmatory tests. When an estimated physiologic quantity matters clinically, use the locally recommended equation or a measured method.

• Corrected Sodium

  Correct measured serum sodium for hyperglycemia with the 1.6 per 100 mg/dL rule.

• BUN Creatinine Ratio

  Compute the blood urea nitrogen to serum creatinine ratio.

• Creatinine-Based Clearance

  Compute renal creatinine clearance as urine volume times urine creatinine divided by plasma creatinine and the collection time in minutes.