Anion Gap Calculator
Calculate the anion gap from sodium, chloride, and bicarbonate, with optional albumin correction. Used to diagnose and classify metabolic acidosis in clinical settings.
Anion gap
16.0
Educational tool. Not a substitute for clinical judgment, professional diagnosis, or treatment. Always verify with current guidelines.
How to use the anion gap calculator
Enter Na, Cl, HCO3 (mEq/L). K and albumin are optional. Albumin entry triggers a corrected anion gap.
Formula & explanation
AG = (Na + K) − (Cl + HCO3). K is conventionally omitted. Albumin-corrected AG = AG + 2.5 × (4 − albumin).
Examples
Na 140, Cl 100, HCO3 24 → AG = 16. Normal range typically 8–12 (without K).
Frequently asked questions
- Why correct for albumin?
- Albumin contributes most of the unmeasured anions; hypoalbuminemia falsely lowers the gap.
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