These equations allow an estimation of creatinine clearance based on age, body weight and serum creatinine levels.


estimated creatinine clearance for males =

= ((140 - (age in years)) * (body weight in kg) / (72 * (serum creatinine in mg/dL))) mL/min


estimated creatinine clearance for females =

= ((0.85) * (140 - (age in years)) * (body weight in kg) / (72 * (serum creatinine in mg/dL))) mL/min =

= (140 - (age in years)) * (body weight in kg) / (85 * (serum creatinine in mg/dL))) mL/min


Note: In the original reference, the formula is NOT per 1.73 meters-squared.



• Body weight is the adjusted body mass (use ideal body weight if current body weight exceeds the ideal body weight, else use the current body weight)

• According to Robert et al (see below), a serum creatinine of 1 mg/dL should be used if the serum creatinine is under 1 mg/dL.

• According to Zawada, the calculated clearance should be reduced in patients with spinal cord injuries (20% if paraplegic; 40% if quadraplegic); source not given


GFR in mL/min

renal function

males 90-139;

females 80-125


52 - 62.5

slight impairment

42 - 52

mild impairment

28 - 42

moderate impairment

< 28

severe impairment



• This applies for adults 20-100 years of age.


According to Robert et al (1993), using the lower value of actual vs ideal body weight and using a serum creatinine value of 1 mg/dL for actual serum creatinine values < 1 mg/dL, the GFR was more accurately predicted in critically ill patients using the Cockcraft-Gault equation rather than a 24 hour measured creatinine clearance; the latter tended to overestimate the actual clearance in many patients.


To read more or access our algorithms and calculators, please log in or register.