Health

TTKG Calculator

Assess renal potassium excretion.

Urine K (mEq/L)

Serum K (mEq/L)

Urine Osm (mOsm/kg)

Serum Osm (mOsm/kg)

TTKG

TTKG = (Urine K / Serum K) / (Urine Osm / Serum Osm). Valid when urine Osm > serum Osm. In hyperkalemia: TTKG < 7 = renal cause. In hypokalemia: TTKG > 3 = renal wasting. Helps differentiate renal vs extra-renal causes of potassium disorders. Note: some recent evidence questions TTKG validity.