Anion Gap Calculator
Calculate anion gap from electrolyte values
About this calculator
An anion gap calculator determines the difference between measured cations and anions in blood serum, helping healthcare professionals diagnose metabolic disorders and acid-base imbalances. This important diagnostic tool uses sodium, chloride, and bicarbonate levels to calculate the anion gap, which normally ranges from 8-16 mEq/L. Abnormal values can indicate conditions like diabetic ketoacidosis, kidney disease, or poisoning, making it essential for clinical assessment and patient monitoring.
How to use
Enter your patient's serum electrolyte values including sodium (Na+), chloride (Cl-), and bicarbonate (HCO3-) levels in mEq/L or mmol/L. The calculator will automatically compute the anion gap using the formula: Anion Gap = Na+ - (Cl- + HCO3-). Review the result and compare it to normal reference ranges for clinical interpretation.
Frequently asked questions
What is a normal anion gap range?
The normal anion gap typically ranges from 8-16 mEq/L, though some laboratories use 6-12 mEq/L depending on testing methods and reference standards used.
What causes a high anion gap?
High anion gap (>16 mEq/L) often indicates metabolic acidosis from conditions like diabetic ketoacidosis, lactic acidosis, kidney failure, or methanol/ethylene glycol poisoning.
Should potassium be included in anion gap calculation?
Most modern calculations exclude potassium since its concentration is relatively low and doesn't significantly affect the gap, though some formulas include it.