Creatinine Clearance Calculator (Cockcroft-Gault)

Enter Calculation

Sex Male Female

Age (years)

Weight (kg)

Serum Creatinine (mg/dL)

Results

Estimated Creatinine Clearance

74.07

mL/min

Equation	Cockcroft-Gault

What Is the Creatinine Clearance Calculator?

The Creatinine Clearance Calculator estimates kidney filtration using the Cockcroft-Gault equation, one of the most widely used formulas in clinical medicine and pharmacy. Creatinine clearance (CrCl) approximates the glomerular filtration rate (GFR) and is frequently used to adjust drug dosing, screen for chronic kidney disease, and monitor renal function. This tool is intended as an educational estimate and should not replace professional medical judgment.

How to Use It

Enter the patient's age in years, body weight in kilograms, serum creatinine in mg/dL, and select sex. The calculator instantly returns the estimated creatinine clearance in mL/min. For female patients the result is multiplied by \(0.85\) to account for typically lower muscle mass.

The Formula Explained

The Cockcroft-Gault equation is:

$$\text{CrCl} = \frac{\left(140 - \text{Age}\right) \times \text{Weight} \times \text{sexFactor}}{72 \times \text{Serum Creatinine}}$$

Here age is in years, weight in kilograms, serum creatinine in mg/dL, and the sex factor is \(0.85\) for females and \(1.0\) for males. A lower creatinine clearance indicates poorer kidney function.

The Cockcroft-Gault equation combines age, weight, sex, and serum creatinine into a single clearance estimate.

Creatinine clearance estimates how efficiently the kidneys filter creatinine from the blood.

Worked Example

Consider a 60-year-old male weighing 80 kg with a serum creatinine of 1.2 mg/dL.

$$\text{CrCl} = \frac{\left(140 - 60\right) \times 80 \times 1}{72 \times 1.2} = \frac{80 \times 80}{86.4} = \frac{6400}{86.4} \approx 74.07 \text{ mL/min}$$

If the same patient were female, the result would be \(74.07 \times 0.85 \approx 62.96\) mL/min.

FAQ

Should I use actual or ideal body weight? Clinicians often use ideal or adjusted body weight in obese patients; this calculator uses whatever weight you enter, so apply clinical judgment.

What is a normal creatinine clearance? Roughly 90–140 mL/min for adult males and 80–125 mL/min for adult females, declining with age.

Is CrCl the same as GFR? No, but CrCl is a commonly used estimate of GFR. The Cockcroft-Gault equation slightly overestimates true GFR because creatinine is also secreted by the tubules.