- Cockcroft and Gault Equation Creatinine clearance for males = (140 - age)(weight in kg) (72)(serum creatinine in mg/dL) Creatinine clearance for females = 140 - age)(weight in kg)(0.85) (72)(serum creatinine in mg/dL) Moderate renal impairment is calculated creatinine clearance 30-50 mL/min (32). Mild renal impairment is calculated creatinine clearance 51-80 mL/min (32).