Arithmetic support

Anion gap calculator

Calculate the transparent anion-gap arithmetic result from sodium, chloride, and bicarbonate. This tool does not apply a reference interval, diagnose an acid-base disorder, or direct treatment.

Educational support only. Verify with clinical judgment and current references.
Safety checks
  • Arithmetic only; no reference interval, diagnosis, or treatment direction is applied.
  • Confirm laboratory units and specimen context before using the arithmetic result.
  • This calculator does not retain patient records or results.
Basis and limits
  • Calculation: AG = Na⁺ − (Cl⁻ + HCO₃⁻).
  • Units: enter sodium, chloride, and bicarbonate in the same mEq/L laboratory unit path.
  • Scope: this tool provides arithmetic only. It does not apply albumin correction, delta-ratio thresholds, a reference interval, a diagnostic classification, or a treatment recommendation.
Formula audit trail

Last reviewed: May 2026

Scope: arithmetic support only. Verify laboratory units and any diagnostic interpretation against current references and clinical judgment.