How to use this calculator
- Enter or choose age.
- Enter or choose sex.
- Enter or choose weight.
- Enter or choose weight in.
- Enter or choose serum creatinine.
- The estimated creatinine clearance updates as you type. Use Copy result or Share to keep it.
Method
CrCl (mL/min) = (140 − Age) × Weight (kg) ÷ (72 × SCr in mg/dL), × 0.85 if female; SCr mg/dL = µmol/L ÷ 88.4
- Age
- years (adults)
- Weight
- kg (1 lb = 0.45359237 kg)
- SCr
- serum creatinine at steady state
Worked example
- (140 − 60) × 72 = 5,760.
- 72 × 1.0 = 72.
- 5,760 ÷ 72 = 80 mL/min (male, so no 0.85 factor); 80 ÷ 60 = 1.33 mL/s.
A 60-year-old man weighing 72 kg with a serum creatinine of 1.0 mg/dL has an estimated creatinine clearance of 80 mL/min.
What the result means
Cockcroft–Gault creatinine clearance is the measure many drug labels use for renal dose adjustment. For staging chronic kidney disease, laboratories report an eGFR (for example CKD-EPI 2021) instead, which is not interchangeable.
Assumptions and limits
- Serum creatinine is stable (not in acute kidney injury).
- The weight entered is the one your protocol or the drug label specifies.
- Derived in adults in 1976; less accurate at extremes of age, weight or muscle mass, in pregnancy and in unstable kidney function.
- Creatinine assays have changed since the equation was developed, which can raise estimates slightly.
Questions
Which weight should I use?
The original study used actual body weight. In obesity, many protocols use ideal or adjusted body weight; follow the drug label or your local guideline.
How is this different from eGFR?
eGFR equations estimate glomerular filtration indexed to 1.73 m² of body surface area. Cockcroft–Gault estimates unindexed creatinine clearance in mL/min, the basis of many drug-dosing tables.
Sources
Please note: This is a general screening estimate for adults, not medical advice or a diagnosis. Talk to a qualified health professional about your health.