Health

Anion Gap Calculator

Anion gap with albumin correction and delta ratio.

Enter your values

Results update instantly as you type — no submit needed.

Results
Anion gap
12 mmol/L
Albumin-corrected gap
12 mmol/L
Interpretation
Normal
Delta ratio
n/a

Working

  1. 1AG = 140 − (104 + 24) = 12

Quick answer

Anion gap = Na − (Cl + HCO₃); normal is 8–12 mmol/L, and it should be corrected upward by 2.5 for every 1 g/dL that albumin is below 4.

AG = Na⁺ − (Cl⁻ + HCO₃⁻)

How to use the Anion Gap Calculator

  1. 1Enter sodium, chloride and bicarbonate from the metabolic panel.
  2. 2Add albumin for correction.
  3. 3Read the corrected gap and delta ratio.

Frequently asked questions

Why correct for albumin?

Albumin is the main unmeasured anion. Hypoalbuminaemia masks a raised gap, hiding a true acidosis.

What does the delta ratio tell me?

Below 0.4 suggests a pure normal-gap acidosis; above 2 suggests a coexisting metabolic alkalosis.