Anion Gap Calculator

Calculate anion gap and assess for metabolic acidosis. Includes delta-delta ratio.

Sodium Na⁺ (mEq/L) (mEq/L)

Chloride Cl⁻ (mEq/L) (mEq/L)

Bicarbonate HCO₃⁻ (mEq/L) (mEq/L)

Albumin (g/dL, for correction) (g/dL)

Normal = 4 g/dL

Please check your inputs and try again.

Worked Examples

Example 1: DKA: Na=140, Cl=100, HCO3=14, Alb=4

AG=26, corrected=26

Result: HAGMA — delta-delta=1.4

High AG from ketoacidosis

Example 2: Normal: Na=140, Cl=103, HCO3=24

AG=13 borderline

Result: Normal to borderline

Check albumin for correction

Frequently Asked Questions

MUDPILES mnemonic for HAGMA?

Methanol, Uremia, Diabetic ketoacidosis, Propylene glycol, Isoniazid/Iron, Lactic acidosis, Ethylene glycol, Salicylates. These are the major causes of high anion gap metabolic acidosis.

Why correct for albumin?

Albumin is a major unmeasured anion. Low albumin artificially lowers the AG. For every 1 g/dL albumin below normal (4), add 2.5 to the calculated AG. Hypoalbuminemia can mask HAGMA.