The Cockcroft-Gault equation allows the creatinine clearance to be estimated from the serum creatinine in a patient with a stable serum creatinine:
(140 - age) x lean body weight [kg]
CCr (mL/min) = —————————————————————————
Cr [mg/dL] x 72
This formula takes into account the increase in creatinine production with increasing weight, and the decline in creatinine production with age.
For women, the formula requires multiplication by 0.85 to account for smaller muscle mass compared to men.
The equation is not adjusted for body surface area. Therefore to compare normal values, the calculation should be adjusted for body surface area. Normalization for body surface increases the accuracy of this equation, particularly among those with decreased renal function.