ToolsCalculators
Anion gap (with albumin correction)
Serum anion gap, corrected for albumin.
Anion gap (with albumin correction)
Sodium
mmol/L
Chloride
mmol/L
Bicarbonate
mmol/L
Albumin (optional)
Complete the fields above to see the result.
When to use
- Evaluating metabolic acidosis and classifying it as high or normal anion gap.
Formula
Anion gap = Na⁺ − (Cl⁻ + HCO₃⁻). Corrected = anion gap + 2.5 × (4.0 − albumin [g/dL]).
Pearls and pitfalls
- Hypoalbuminaemia lowers the measured gap by roughly 2.5 mmol/L per 1 g/dL fall in albumin, and can mask a significant acidosis.