🧬 Anion Gap Calculator
Calculate the serum anion gap from a basic metabolic panel using sodium, chloride, and bicarbonate values.
How the anion gap is calculated
The standard anion gap formula is: Anion Gap = Sodium – (Chloride + Bicarbonate), using values from a basic metabolic panel measured in mEq/L. Some labs use a version that also includes potassium: (Sodium + Potassium) – (Chloride + Bicarbonate), which this calculator also shows when a potassium value is entered.
Why it matters
A typical reference range is roughly 8-12 mEq/L, though normal ranges vary slightly between laboratories. An elevated anion gap can point toward conditions like diabetic ketoacidosis, lactic acidosis, kidney failure, or certain toxic ingestions, while a low anion gap is less common and has its own set of possible causes.
This calculator is intended for general educational and reference purposes only and does not diagnose any medical condition. Lab results should always be interpreted by a qualified healthcare professional in the context of the full clinical picture.