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Anion Gap Calculator
Serum AG · Albumin-corrected AG · Delta ratio · Mixed disorder detection
Enter Serum Electrolytes & Chemistry
mEq/L
Normal: 136–145
mEq/L
Normal: 98–106
mEq/L
Normal: 22–28
g/dL
Normal: 3.5–5.0. Leave blank to skip albumin correction.
Formulas & Reference
Anion Gap
AG = Na⁺ − (Cl⁻ + HCO₃⁻) · Normal: 8–12 mEq/L
Corrected AG
Corrected AG = AG + 2.5 × (4.0 − Albumin) · Adjusts for hypoalbuminaemia
Delta Ratio
Δ/Δ = (AG − 12) ÷ (24 − HCO₃⁻) · Only valid when AG is elevated
| Delta Ratio | Interpretation |
|---|---|
| < 0.4 | Normal AG metabolic acidosis (hyperchloraemic) |
| 0.4–0.8 | Combined high AG + normal AG acidosis |
| 0.8–2.0 | Pure high AG metabolic acidosis (expected range) |
| > 2.0 | High AG acidosis + concurrent metabolic alkalosis (or pre-existing HCO₃ elevation) |
High AG Acidosis — Mnemonic: MUDPILES / GOLDMARK
Methanol · Uraemia · DKA · Propylene glycol · Isoniazid / Iron · Lactic acidosis · Ethylene glycol · Salicylates
Source: Emmett M, Szerlip H. UpToDate 2024; Rose BD. Clinical Physiology of Acid-Base Disorders, 5th ed.