- Renal function: Age-adjusted normal serum creatinine according to the following table or a creatinine clearance greater than or equal to 60 ml/min/1.73 m^2. Age (years) Maximum serum creatinine (mg/dl) less than or equal to 5 0.8 greater than 5, less than or equal to 10 1.0 greater than 10, less than or equal to15 1.2, greater than 15 1.5