Creatinine Clearance Calculator
Estimate creatinine clearance using the Cockcroft–Gault equation with age, sex, weight, height, and serum creatinine.
Results
This calculator is for educational estimation only and is not medical advice. Cockcroft–Gault creatinine clearance is not the same as lab-reported eGFR, is not body-surface-area adjusted, and may be unreliable when serum creatinine is not stable. Always confirm medication dosing or kidney function decisions with a qualified clinician.
Use this Creatinine Clearance Calculator to estimate creatinine clearance (CrCl) using the Cockcroft–Gault equation. The calculator estimates kidney filtration function using age, sex, body weight, and serum creatinine values.
Medical Warning: This Creatinine Clearance Calculator is for educational estimation only. It does not diagnose kidney disease and must not be used alone to start, stop, or change medication dosing. Cockcroft–Gault creatinine clearance is different from lab-reported eGFR, is not automatically body-surface-area adjusted, and may be unreliable when serum creatinine is changing. Always confirm kidney-function interpretation and medication dosing with a qualified clinician or pharmacist.
Reviewed by: AjaxCalculators Editorial Team
Last updated: May 2026
Method source: Cockcroft–Gault creatinine clearance equation
Editorial standards: Built with transparent formulas, assumptions, examples, references, and limitations.
What Is Creatinine Clearance?
Creatinine clearance estimates how efficiently the kidneys remove creatinine from the blood. Creatinine is a waste product produced from normal muscle metabolism and removed through kidney filtration.
Creatinine clearance may be used as an estimate of kidney filtration function and may help clinicians evaluate medication dosing considerations.
Cockcroft–Gault Formula
For males:
CrCl = ((140 − age) × weight in kg) ÷ (72 × serum creatinine)
For females:
CrCl = Male result × 0.85
Creatinine clearance is typically expressed as mL/min.
Worked Example
| Input | Value |
|---|---|
| Sex | Male |
| Age | 65 |
| Weight | 180 lb |
| Height | 70 in |
| Serum creatinine | 1.2 mg/dL |
Estimated result:
70.9 mL/min
Kidney Function Interpretation Guide
| CrCl | General Interpretation |
|---|---|
| 90+ | Typical range |
| 60–89 | Mild reduction |
| 30–59 | Moderate reduction |
| 15–29 | Severe reduction |
| Below 15 | Kidney failure range |
Creatinine Clearance vs eGFR
| Measure | Common Use |
|---|---|
| Creatinine Clearance | Medication dosing decisions |
| eGFR | Kidney disease assessment |
Weight Methods Used
| Weight Type | Description |
|---|---|
| Actual body weight | Current measured body weight |
| Ideal body weight | Estimated ideal weight formula |
| Adjusted body weight | Modified estimate sometimes used for obesity |
Why CrCl Should Not Be Used Alone for Medical Decisions
Creatinine clearance estimates can help explain how the Cockcroft–Gault equation works, but clinical decisions require more context. A healthcare professional may consider the official lab result, recent creatinine trend, age, body size, muscle mass, pregnancy status, acute illness, medication list, and the specific dosing guidance for a drug.
For medication dosing, different drugs may use different kidney-function cutoffs or preferred equations. Do not use this calculator as a replacement for a clinician, pharmacist, laboratory report, or official prescribing guidance.
How to Use This Calculator
- Select sex.
- Enter age.
- Enter body weight and units.
- Enter height.
- Enter serum creatinine.
- Select weight method.
- Click Calculate.
How to Interpret Results
| Result | Meaning |
|---|---|
| Creatinine clearance | Estimated filtration value |
| Interpretation | General kidney function category |
| Weight used | Selected formula body weight |
When Results May Be Less Reliable
- Rapidly changing serum creatinine
- Acute kidney injury
- Pregnancy
- Extremely high or low muscle mass
- Amputation
- Severe illness
- Edema
- Malnutrition
Common Mistakes
- Confusing CrCl with eGFR
- Using incorrect units
- Ignoring changing creatinine values
- Assuming estimates replace medical evaluation
Assumptions and Limitations
- The equation assumes stable serum creatinine.
- Results are estimates only.
- Different methods may use different body weights.
- Clinical interpretation may vary.
Practical Uses
- Medication dose consideration
- Kidney function estimation
- Educational use
- Understanding laboratory values
References
- Cockcroft DW, Gault MH — Prediction of Creatinine Clearance from Serum Creatinine
- National Kidney Foundation — Estimated Glomerular Filtration Rate
- KDIGO — CKD Evaluation and Management Guideline
- NIDDK — Kidney Disease Information
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Frequently Asked Questions
Is creatinine clearance the same as eGFR?
No. They are different estimates and often used for different purposes.
Can this calculator diagnose kidney disease?
No. It estimates filtration only.
Why does body weight matter?
Weight is part of the Cockcroft–Gault equation.
Why does serum creatinine affect results?
Creatinine levels influence estimated kidney filtration.
Can changing creatinine levels reduce accuracy?
Yes. Rapid changes may make estimates unreliable.
Disclaimer: This Creatinine Clearance Calculator provides an educational estimate only and does not replace medical evaluation, laboratory interpretation, pharmacy review, or clinical decision-making. Cockcroft–Gault creatinine clearance can differ from eGFR and may be inaccurate in acute kidney injury, pregnancy, unstable serum creatinine, unusual muscle mass, edema, amputation, malnutrition, or severe illness. Always confirm medication dosing, kidney-function interpretation, and treatment decisions with a qualified healthcare professional.