Fractional Excretion of Urea (FEUrea).
Quick and easy to use FEUrea calculator. Enter required data to get FEUrea percentage result:
Serum Urea/BUN: mgdL or mmol/L
Serum Creatinine: mgdL or µmol/L
Urine Urea: mgdL or mmol/L
Urine Creatinine: mgdL or µmol/L
No fuss calculator. It does what it says on the tin.