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Anion Gap Calculator
Hematology / Acid-Base
The anion gap estimates unmeasured anions in serum and helps classify metabolic acidosis. A corrected anion gap adjusts for hypoalbuminemia. The delta-delta ratio identifies mixed acid-base disorders.
Formula
AG = Na − (Cl + HCO₃)
Normal: 8–12 mEq/L
Corrected AG = AG + 2.5 × (4.0 − Albumin)
Delta-Ratio = (AG − 12) / (24 − HCO₃)
Normal: 8–12 mEq/L
Corrected AG = AG + 2.5 × (4.0 − Albumin)
Delta-Ratio = (AG − 12) / (24 − HCO₃)
Reference
| Status | Anion Gap | Clinical Significance |
|---|---|---|
| Low | <8 mEq/L | Hypoalbuminemia, lithium toxicity, multiple myeloma |
| Normal | 8–12 mEq/L | Normal |
| High | >12 mEq/L | HAGMA — see MUDPILES |
Clinical Notes
MUDPILES (High AG): Methanol, Uremia, DKA, Propylene glycol, Isoniazid/Iron, Lactic acidosis, Ethylene glycol, Salicylates
HARDASS (Normal AG): Hyperalimentation, Addison's, Renal tubular acidosis, Diarrhea, Acetazolamide, Spironolactone, Saline
For educational use only. Clinical decisions must incorporate full patient evaluation.
