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Creatinine Clearance Calculator

Estimate creatinine clearance with the Cockcroft-Gault equation, using age, weight, sex, and serum creatinine.

Patient values

Equation: CrCl = ((140 - age) x weight x F) / (72 x serum creatinine), with F = 0.85 for females.

Result

Creatinine clearance--
Sex factor applied--

This estimate uses actual body weight. Clinicians sometimes use ideal or adjusted body weight. It does not set any medication dose.

How this calculator works

The Cockcroft-Gault equation estimates how quickly the kidneys clear creatinine from the blood. It uses age, body weight, sex, and serum creatinine, and is still widely used as a reference for kidney function and drug dosing.

Formula. CrCl (mL/min) = ((140 - age) x weight in kg x F) / (72 x serum creatinine in mg/dL). F is 0.85 for females and 1 for males.

For example, a 60-year-old male weighing 70 kg with a serum creatinine of 1.0 mg/dL gives CrCl = ((140 - 60) x 70 x 1) / (72 x 1.0) = 5600 / 72, which is about 78 mL/min.

Source

The equation was published by Cockcroft DW and Gault MH, "Prediction of creatinine clearance from serum creatinine" (Nephron, 1976). For background on kidney function tests, see the National Kidney Foundation and NIDDK: Kidney Disease.

Important limits

Cockcroft-Gault can be less accurate at the extremes of body weight, in older adults, in pregnancy, and when serum creatinine is changing quickly. The choice of body weight (actual, ideal, or adjusted) affects the result and is a clinical decision.

Medical disclaimer. This tool is for educational purposes only, uses published clinical equations, and is not a substitute for professional medical advice. Consult a qualified healthcare provider.
Common questions

FAQs

What is the Cockcroft-Gault formula?

Creatinine clearance (mL/min) = ((140 - age) x weight in kg x F) / (72 x serum creatinine in mg/dL), where F is 0.85 for females and 1 for males. It was published by Cockcroft and Gault in 1976.

Which weight should I use?

The original equation uses actual body weight. In some clinical settings, ideal or adjusted body weight is used instead, particularly for patients who are underweight or have obesity. This is a clinical judgment best made by a healthcare provider or pharmacist.

How is creatinine clearance different from eGFR?

Cockcroft-Gault estimates creatinine clearance and is still widely used for drug dosing. eGFR equations such as CKD-EPI estimate glomerular filtration rate and are normalized to body surface area. They can give different numbers and are used for different purposes.

Can this tool decide my medication dose?

No. This calculator only applies a published equation. It does not account for your full clinical picture and does not set or adjust any medication dose. A qualified healthcare provider or pharmacist must make dosing decisions.