Anion Gap Calculator

Calculates serum anion gap with or without potassium and shows each arithmetic step.

Inputs

Color mode links each input to the matching equation term and solving arithmetic.

Equation and Work

Equation:
Solving steps:
Anion gap
—
mEq/L
Reference band
—
status
Anion sum
—
mEq/L
Normal/reference: 10–14 mEq/L without potassium; 15–20 mEq/L when potassium is included. Some references use 12 ± 4 mEq/L / 8–16 mEq/L as an acceptable range.

Clinical Significance

Serum anion gap with or without potassium and shows each arithmetic step.

This calculator expands that idea by identifying the relevant measured values, substituting the selected inputs, and carrying the arithmetic through in the solving steps.

Use anion gap to help evaluate metabolic acidosis. Increased gap suggests added fixed acids; normal gap often reflects bicarbonate loss/hyperchloremia.

Albumin and local laboratory methodology affect interpretation. This calculator performs the equation only and does not diagnose the cause of acidosis.

References (APA 7th Edition)

  1. Chang, D. W. (2020). Respiratory Care Calculations (Revised 4th ed.). Jones & Bartlett Learning. Formula content adapted from the uploaded text/reference packet.