Anion Gap Calculator
Anion gap with albumin correction and delta ratio.
Enter your values
ⓘ Live results
Results
- Anion gap
- 12 mmol/L
- Albumin-corrected gap
- 12 mmol/L
- Interpretation
- Normal
- Delta ratio
- n/a
Working
- 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
- 1Enter sodium, chloride and bicarbonate from the metabolic panel.
- 2Add albumin for correction.
- 3Read the corrected gap and delta ratio.
Worked example
Using the values the calculator loads with:
Inputs
- Sodium140 mmol/L
- Chloride104 mmol/L
- Bicarbonate24 mmol/L
- Albumin4.0 g/dL
Results
- Anion gap12 mmol/L
- Albumin-corrected gap12 mmol/L
- InterpretationNormal
- Delta ration/a
- AG = 140 − (104 + 24) = 12
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.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.