Creatinine Clearance Calculator — Cockcroft-Gault (Drug Dosing)
The Cockcroft-Gault equation estimates creatinine clearance from age, weight, and serum creatinine. Although CKD-EPI 2021 is the preferred equation for chronic kidney disease staging, the FDA continues to reference Cockcroft-Gault on most drug labels for renal-dose adjustment. Cockcroft-Gault returns CrCl in mL/min (not normalised to body surface area), with a 0.85 multiplier for female sex from the original 1976 derivation. Clinically, the equation underperforms in obesity, oedema, and at extremes of muscle mass; the corresponding CKD-EPI eGFR or measured CrCl may be more reliable in those settings.
This tool is for educational and decision-support use only. It does not replace independent clinical judgement. Always verify against the current guideline, FDA label, or specialty reference cited below before acting. Do not enter patient identifiers (name, MRN, dates of service).
Tool
Who this is for
- Pharmacists and clinicians dosing renally cleared medications
- Internal medicine residents
- Hospitalists and nephrology consult services
How to interpret the result
| Score / band | Interpretation |
|---|---|
| ≥ 60 | Most renally cleared drugs require no adjustment unless the label specifies otherwise. |
| 30–59 | Moderate impairment — many drug labels specify dose reduction or interval extension. |
| 15–29 | Severe impairment — commonly large dose reductions or alternative agents. |
| < 15 / dialysis | Specific dialysis-aware dosing protocols apply. |