Anion Gap Calculator
Anion gap, albumin-corrected gap and delta ratio.
Enter your values to see the result.
Anion gap = Na − (Cl + HCO₃). The delta ratio (ΔAG ÷ ΔHCO₃) helps spot a mixed acid–base disorder. Reference ranges differ between analyzers, so use your laboratory's normal value. For education and clinical decision support only. Results do not replace professional judgment, local protocols or the product information, so always verify doses and values before acting on them.
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How to use the Anion Gap Calculator
Anion gap, albumin-corrected gap and delta ratio.
- 1 Enter sodium, chloride and bicarbonate (and potassium if your lab includes it).
- 2 Add albumin to correct the gap for hypoalbuminemia.
- 3 Read the gap, the delta ratio and the interpretation.
Example and practical tips
Na 140, Cl 100 and HCO₃ 14 give an anion gap of 26 mmol/L, a high anion gap metabolic acidosis with a delta ratio of 1.4.
Frequently asked questions
What is a normal anion gap?
Usually about 8–16 mmol/L without potassium, but it varies by analyzer, so use your laboratory’s range.
Why correct for albumin?
Albumin is the main unmeasured anion. Each 1 g/dL fall lowers the gap by about 2.5, which can hide a high-gap acidosis.
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