Creatinine Clearance Calculator

Cockcroft and Gault's 1976 paper reported values 15% lower in women, so the result is multiplied by 0.85. StatPearls describes it as a correction for the lower creatinine clearance in women.

Australian Prescriber's 2019 review says that with a BMI over 30 kg/m², or weight over 120 kg, Cockcroft-Gault on actual body weight overestimates GFR, and recommends adjusted ideal body weight: IBW + 0.4 × (actual weight − IBW). The calculator switches to that weight when you tick the box, enter a height and the BMI is over 30.

The same review rates Cockcroft-Gault with actual body weight as acceptable when BMI is under 18.5 or weight is under 60 kg. Where a creatinine-based estimate may be unreliable, KDIGO 2024 suggests an equation that adds cystatin C, or a measured GFR.

StatPearls notes that creatinine is also secreted by the kidney tubules, so creatinine clearance overestimates true GFR by about 10% to 20%. A figure such as 73.4 mL/min suggests more precision than the estimate has, so the result is shown to the nearest whole number.

No. The 1976 formula was derived from patients aged 18 to 92, and the calculator stops below 18. StatPearls says GFR in children is usually estimated with the CKiD (bedside Schwartz) equation, which uses serum creatinine and height.