Creatinine Clearance Calculator (Cockcroft-Gault)
Estimates creatinine clearance using the Cockcroft-Gault equation — still widely used for renal drug-dosing decisions — from age, weight, sex and serum creatinine.
Quick answer
Creatinine clearance estimates kidney filtration for drug-dosing decisions. This calculator uses the Cockcroft-Gault equation: CrCl = (140 − age) × weight in kg × (0.85 if female) ÷ (72 × serum creatinine in mg/dL). It uses actual body weight and is not corrected to body surface area.
Cockcroft-Gault inputs
How to use the Creatinine Clearance calculator
- 1Enter age, weight, sex and creatinine. Enter age in years, body weight (kg or lb), sex, and serum creatinine (mg/dL or µmol/L).
- 2Read the creatinine clearance. The tool applies the Cockcroft-Gault equation and shows the estimate in mL/min.
- 3Use it for dosing decisions with a professional. Many drug labels were validated against Cockcroft-Gault, so it is still used for renal dose adjustment — a decision for a clinician or pharmacist.
Medical disclaimer: This is general health information, not medical advice. It does not diagnose or treat any condition, and the results are estimates based on public reference formulas. Always consult a qualified doctor about your individual health. If you think you may have a medical emergency, contact your local emergency services immediately.
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Book a consultationFrequently asked questions
Why use Cockcroft-Gault instead of eGFR?⌄
Many medication dosing guidelines were originally developed and validated using Cockcroft-Gault creatinine clearance, so it is still preferred for renal drug dosing even though CKD-EPI eGFR is preferred for staging chronic kidney disease.
Which weight should I use?⌄
Cockcroft-Gault uses actual body weight, but in obesity, oedema or very low muscle mass an adjusted or ideal body weight is often used instead. A clinician or pharmacist chooses the appropriate weight.
Why is the result different from my eGFR?⌄
Creatinine clearance (Cockcroft-Gault) uses actual weight and is not normalised to 1.73 m² body surface area, whereas CKD-EPI eGFR is normalised. They are different estimates and can legitimately differ.
Sources & validation
This calculator reproduces the published Creatinine Clearance score, validated for creatinine clearance for renal drug-dose adjustment (Cockcroft-Gault).
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