Variables
Description
What is this formula?
The Cockcroft–Gault equation estimates creatinine clearance, which is commonly used as an approximation of kidney function and drug dosing capability.
When to use it
Use this formula when adjusting medication dosages, assessing renal function, or estimating creatinine clearance in adults.
Example
Data:
Age = 65 years
W = 70 kg
SCr = 1.2 mg/dL
Formula:
CrCl = ((140 − Age) × W) / (72 × SCr)
Substitution:
CrCl = ((140 − 65) × 70) / (72 × 1.2)
CrCl = 5250 / 86.4
Result:
CrCl = 60.8 mL/min
The estimated creatinine clearance is 60.8 mL/min.
Applications
- Drug dosage adjustment
- Renal function assessment
- Nephrology
- Clinical pharmacology
- Internal medicine
Note
This is the original Cockcroft–Gault equation for adult males. For females, the result is traditionally multiplied by 0.85. The equation provides an estimate rather than a direct measurement of glomerular filtration and may be less accurate in obesity, cachexia, amputations, pregnancy, or rapidly changing kidney function. Newer equations such as MDRD and CKD-EPI are often used for estimating glomerular filtration rate.