Anion Gap Calculator
Anion Gap Calculator for Nephrology. Use the result to help categorize metabolic acidosis and guide evaluation for lactate, ketones, renal failure, toxins, and mixed acid-base disorders.
How this calculator works
The anion gap estimates unmeasured anions from routinely measured electrolytes, commonly sodium minus chloride and bicarbonate.
Inputs used
- Sodium
- Chloride
- Bicarbonate
- Albumin when correcting the gap
Clinical interpretation
Use the result to help categorize metabolic acidosis and guide evaluation for lactate, ketones, renal failure, toxins, and mixed acid-base disorders.
Limitations and safety notes
Albumin, lab method, and mixed disorders affect interpretation. Correct for hypoalbuminemia when clinically relevant.
References
- Kraut JA, Madias NE. Serum anion gap: its uses and limitations in clinical medicine. Clin J Am Soc Nephrol. 2007.
Editorial review and citation methodology
Reviewed by the Quick Medical Calculator Editorial Team. Last reviewed: June 19, 2026. The review checks calculator inputs, intended population, interpretation, limitations, and source alignment.
- Prefer original validation studies for scoring systems and prediction tools.
- Use current specialty society guidance, transplant allocation policy, public health guidance, or regulator resources when they govern clinical use.
- Include limitations and safety notes when a calculator is population-specific, context-dependent, or unsuitable as a standalone decision tool.