Creatinine Clearance (Cockcroft-Gault)
Estimate creatinine clearance (CrCl) in mL/min using age, sex, weight, and serum creatinine.
Educational use only. This estimate does not replace clinical judgment or professional medical advice.
What is a creatinine clearance calculator?
A creatinine clearance calculator estimates how well your kidneys are filtering waste from the blood. The result is usually shown in mL/min, and it helps clinicians make decisions such as medication dosing, especially for drugs cleared by the kidneys.
This calculator uses the widely known Cockcroft-Gault equation, which is commonly used in drug dosing references.
Formula used (Cockcroft-Gault)
For serum creatinine in mg/dL:
- Male: CrCl = ((140 − age) × weight in kg) / (72 × serum creatinine)
- Female: Multiply the male result by 0.85
If you enter serum creatinine in µmol/L, this tool converts it to mg/dL first (mg/dL = µmol/L ÷ 88.4).
How to use this calculator
Step-by-step
- Enter age in years.
- Select sex (as used by the equation coefficient).
- Enter body weight in kilograms.
- Enter serum creatinine and choose the correct unit.
- Optionally enter height to get a BSA-adjusted estimate (mL/min/1.73m²).
After clicking Calculate, you will see the estimated CrCl and a general interpretation range.
How to interpret the result
The categories below are general guidance and are not a diagnosis:
- ≥ 90 mL/min: Normal or near normal filtration range
- 60–89 mL/min: Mildly reduced
- 30–59 mL/min: Moderately reduced
- 15–29 mL/min: Severely reduced
- < 15 mL/min: Kidney failure range
Interpretation depends on symptoms, trend over time, urinalysis, blood pressure, and other labs.
Creatinine clearance vs eGFR
Key differences
- CrCl (Cockcroft-Gault): Often used for medication dosing.
- eGFR (CKD-EPI): Commonly reported by labs for chronic kidney disease staging.
- Results may differ because formulas use different variables and assumptions.
Limitations and important notes
- Estimates can be less accurate in very low or very high muscle mass.
- Acute kidney injury can make static formulas less reliable.
- Hydration status, lab variability, and timing can affect creatinine values.
- Pregnancy, amputations, and severe obesity may require special methods.
When medication safety is critical, clinicians may use additional tests, repeat labs, or measured clearance methods.
Frequently asked questions
Is this the same as a 24-hour urine creatinine clearance test?
No. This page calculates an estimate from blood creatinine and demographics. A 24-hour urine test is a measured method and may be used in selected cases.
Which weight should I use?
Many references use actual body weight, but dosing protocols can differ (actual, ideal, or adjusted body weight) depending on patient context and the specific medication.
Can I use this to diagnose kidney disease?
No. This is a screening and educational estimate only. Diagnosis should come from a qualified healthcare professional.