Creatinine clearance calculator (Cockcroft-Gault)
Estimated creatinine clearance by Cockcroft-Gault, the basis of most renal dosing.
Optional. Used to derive ideal and adjusted body weight.
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This is a reference implementation of a published formula, provided for use by qualified healthcare professionals. It does not diagnose, does not account for the individual circumstances of any patient, and is not a recommendation for treatment. Confirm every result against your own institutional guidance before acting on it. Clinical judgement always takes precedence over a calculator.
About this calculation
Cockcroft-Gault estimates creatinine clearance from age, weight, sex and serum creatinine. It remains the method most drug labels were validated against, which is why renal dose adjustment usually asks for it rather than for eGFR.
Formula
CrCl (mL/min) = [(140 − age) × weight (kg)] ÷ (72 × serum creatinine (mg/dL)), × 0.85 if female
- Source
- Cockcroft DW & Gault MH, Nephron (1976)
- Methodology version
- 1.0.0
- Last reviewed
- 2026-10-28
What this does not account for
- Which weight to use is not settled. Actual weight overestimates clearance in obesity; many references specify ideal or adjusted body weight. All three are shown so the choice is explicit.
- The equation assumes creatinine is at steady state. In acute kidney injury, where creatinine is still moving, it does not reflect current function.
- It was derived in a cohort of mostly white men and performs less well at the extremes of age, muscle mass and body size.
- Creatinine clearance overestimates GFR, because creatinine is secreted by the tubule as well as filtered.
Related tools
eGFR calculator (CKD-EPI 2021)
Estimated GFR by the race-free CKD-EPI 2021 creatinine equation, with CKD stage.
Ideal body weight calculator
Ideal body weight by the Devine formula, with the Robinson and Miller variants.
Adjusted body weight calculator
Adjusted body weight for dosing in obesity, from ideal and actual weight.