Urine Anion Gap Calculator


Anion gap:

Urine Anion Gap

In normal conditions the anion gap is positive. In metabolic acidosis, a positive anion gap points to a renal origin, while a negative anion gap points to an extra-renal origin.

Calculation of the Urine Anion Gap

Urine anion gap is calculated by subtracting the urine concentration of chloride from the concentrations of sodium plus potassium:

= Na+ + K+ − Cl

In contrast to the serum anion gap equation, the bicarbonate is excluded. This is because urine is acidic, so the bicarbonate level would be negligible