Creatinine clearance calculator (Cockcroft-Gault)
Estimate creatinine clearance (CrCl) with the Cockcroft-Gault formula, commonly used as a reference when adjusting renally cleared drug doses. Specific dose-adjustment thresholds are drug-specific, so check the prescribing information.
Estimated CrCl
Enter the values to see the result.
This tool assists calculation. It does not replace clinical judgement and is not a treatment instruction. Check against your institution protocol, reference ranges, and prescribing information. Clinical decisions belong to the treating clinician.
Interpreting the result
- Severely decreased — Many drugs need marked dose adjustment.
- Moderately decreased
- Mildly decreased
- Within normal range
Formula
CrCl = [(140 − Age) × Weight(kg) × (0.85 if female)] / (72 × Creatinine(mg/dL)). This tool uses actual body weight; some protocols use ideal or adjusted body weight.
Frequently asked questions
Which body weight should I use?
The original formula uses actual body weight, but in obesity many protocols use ideal or adjusted body weight. Follow your institution guidance.
How is CrCl different from eGFR?
Cockcroft-Gault estimates creatinine clearance (mL/min) and is still used by many drug labels for dosing, while eGFR (CKD-EPI) is normalized to 1.73m² and used to stage kidney disease.