How this calculator works
Cockcroft-Gault is reproduced with the original 72 denominator and 15% reduction for women. Enter the weight you intend to use; this page does not automatically substitute ideal or adjusted weight or round a low creatinine upward. Height only provides BMI context. The timed method uses the entire collected urine volume and actual collection duration. Neither result is indexed to 1.73 m². Estimates are unreliable when creatinine is changing rapidly and are not medication dosing instructions. The result is an estimate for information only and is not medical advice.
Formula
Cockcroft-Gault: CrCl (mL/min) = (140 - age in years) × weight in kg / (72 × serum creatinine in mg/dL), multiplied by 0.85 for women. Measured CrCl = urine creatinine / serum creatinine × urine volume in mL / collection minutes. Inverse modes rearrange the selected equation.
Worked example
For a 60-year-old man weighing 72 kg with serum creatinine 1 mg/dL: 80 × 72 / 72 = 80 mL/min. The original female factor gives 68 mL/min. Urine creatinine 100, serum 1 mg/dL and 1440 mL over 24 hours give 100 mL/min measured clearance.
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Frequently asked questions
Is this the same as eGFR?
No. Creatinine clearance includes tubular secretion, while eGFR estimates glomerular filtration and is usually indexed to body surface area.
Which weight should I use?
The original equation uses entered body weight. In obesity, oedema or unusual body composition, a clinician must choose an appropriate method; no alternative weight formula is silently applied here.
Does the urine collection have to last 24 hours?
No. Enter the actual collection duration and total volume. Incomplete collection and mismatched serum sampling can substantially distort clearance.