Free Anion Gap Calculator
Calculate the serum anion gap from basic metabolic panel values to help identify metabolic acidosis causes.
mEq/L
mEq/L
mEq/L
g/dL
Anion Gap
12 mEq/L
Albumin-Corrected AG12.0 mEq/L
Delta Ratio (if AG elevated)—
Anion Gap vs Sodium (Na+)
Anion Gap Formula
AG = Na+ - Cl- - HCO3-
Normal Range
Normal anion gap: 8-12 mEq/L (without potassium)
Albumin Correction
Corrected AG = AG + 2.5 x (4.0 - Albumin)
Low albumin can mask an elevated anion gap.
Common Causes of Elevated Anion Gap (MUDPILES)
Methanol, Uremia, Diabetic ketoacidosis, Propylene glycol, Iron/Isoniazid, Lactic acidosis, Ethylene glycol, Salicylates
Example Calculation
Na 140, Cl 104, HCO3 24, Albumin 4.0.
- 01AG = 140 - 104 - 24 = 12 mEq/L
- 02Corrected AG = 12 + 2.5 x (4.0 - 4.0) = 12
- 03Normal anion gap (8-12)
Frequently Asked Questions
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