Fractional Excretion of Sodium (FENa).
Quick and easy to use FENa calculator. Enter the required data to get FENa percentage result:
Plasma Sodium: mmol/L or mEq/L
Plasma Creatinine: mg\dL or µmol/L
Urine Sodium: mmol/L or mEq/L
Urine Creatinine: mg\dL or µmol/L
No fuss calculator. Does what it says on the tin.