How to Use Urinary Anion Gap Calculator
- Enter urine sodium concentration in mmol/L.
- Enter urine potassium concentration in mmol/L.
- Enter urine chloride concentration in mmol/L and review whether the calculated UAG is negative or positive.
Formula & Theory - Urinary Anion Gap Calculator
Urinary Anion Gap Calculator uses this core formula:
UAG = Urine sodium + Urine potassium - Urine chloride
Urinary anion gap is used as a rough surrogate for urinary ammonium excretion in metabolic acidosis evaluation. Chloride often rises when ammonium chloride excretion is high, producing a negative UAG. A positive UAG can suggest impaired renal acid excretion, though the interpretation is imperfect. Ketoacids, hippurate, unusual anions, kidney function, and urine collection conditions can all distort the relationship.
Use Cases for Urinary Anion Gap Calculator
- Distinguishing extra-renal bicarbonate loss from renal tubular acidification problems.
- Teaching why urine chloride matters in metabolic acidosis.
- Reviewing acid-base cases where urine electrolytes are already measured.