Creatinine Clearance (Cockcroft-Gault)

How it is calculated

The tool applies the Cockcroft-Gault equation: CrCl = (140 − age) × weight ÷ (72 × SCr), with age in years, weight in kg and serum creatinine (SCr) in mg/dL. For female patients the result is multiplied by 0.85. The answer is rounded to a whole number and shown in mL/min. It uses exactly the weight you type (it does not switch to ideal or adjusted weight), and any sex other than female is treated as male. Age must be above 0 and at most 120, and weight and creatinine must be above 0, otherwise no result appears.

Common mistakes

• Entering creatinine in µmol/L. The formula's constant 72 is for mg/dL; a lab value like 106 µmol/L (about 1.2 mg/dL) would give a nonsense tiny clearance.
• Entering weight in pounds instead of kg, which inflates the result by roughly 2.2 times.
• Forgetting to set sex to female. The 0.85 factor is skipped by default, so the female result is about 18% too high.
• Reading the result as an eGFR. Cockcroft-Gault gives mL/min for the person's actual size, not an index normalised to 1.73 m², so the two are not interchangeable.
• Using a creatinine from a different day than the weight and age on record, or a value taken while kidney function is changing quickly; the formula assumes a steady state.