Quick answer: Cockcroft-Gault CrCl
The Cockcroft-Gault calculator estimates adult creatinine clearance (CrCl) in mL/min from age, sex, weight, and serum creatinine. It is often used as a quick renal function estimate when medication references specify Cockcroft-Gault CrCl.
This page is for education and calculation support only. Medication dosing and kidney-function interpretation should be checked against local clinical guidance and a qualified clinician.
How to use the Cockcroft-Gault calculator
- Choose sex.
- Enter age in years.
- Enter the weight you intend to use in kilograms.
- Enter serum creatinine in mg/dL.
- Review the estimated CrCl in mL/min.
Cockcroft-Gault formula
CrCl = [ (140 - Age) * Weight ] / [ 72 * Serum Cr ] * (0.85 if Female)
For females, the result is multiplied by 0.85. The equation uses weight as a proxy for creatinine generation, so the chosen weight can materially change the estimate.
Important weight note
Some clinical workflows use actual body weight, ideal body weight, or adjusted body weight depending on body habitus and the medication context. This calculator uses the weight you enter directly. If you are calculating CrCl for drug dosing, confirm which weight basis your protocol expects.
When Cockcroft-Gault may be less reliable
Creatinine-based estimates can be less reliable in people with rapidly changing kidney function, unusual muscle mass, severe malnutrition, amputation, pregnancy, or acute illness. In those situations, clinical teams may prefer measured clearance or another kidney function estimate.