Renal
Creatinine clearance (Cockcroft-Gault)
Cockcroft-Gault estimates creatinine clearance from age, weight, sex and serum creatinine. It is the equation most drug labels are written against, which is why it survives alongside eGFR.
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This calculator is provided for reference and education. It does not replace clinical assessment, examination, current guidelines, local protocol, or professional judgment. Verify every result before acting on it. Nirogix accepts no liability for clinical decisions made using this tool.
The formula
- CrCl = [(140 − age) × weight (kg)] ÷ (72 × serum creatinine mg/dL)
- Multiply by 0.85 for a female patient
Worked example
A 60-year-old man, 70 kg, creatinine 1.2 → (80 × 70) ÷ (72 × 1.2) = 5600 ÷ 86.4 = 65 mL/min
When to use it
- Adjusting a drug dose where the label specifies creatinine clearance
- Any renally cleared drug with a narrow therapeutic index
And when not to
- It uses actual body weight, which overestimates clearance in obesity. Many services use adjusted body weight instead, so be explicit about which you used.
- It is unreliable when creatinine is changing, which is exactly the case in acute kidney injury.
- Low muscle mass in the elderly, the malnourished or an amputee makes creatinine a poor marker of function in either equation.
References
- Prediction of creatinine clearance from serum creatinine — Cockcroft DW & Gault MH, Nephron, 1976
Last reviewed 07/09/2026.
More renal calculators
eGFR (CKD-EPI 2021)
Estimated glomerular filtration rate places kidney function on the CKD staging scale. The default here is the 2021 CKD-EPI creatinine equation, which removed the race coefficient the earlier version carried.
Fractional excretion of sodium (FENa)
FENa is the proportion of filtered sodium the kidney excretes, and it separates pre-renal acute kidney injury from intrinsic tubular injury. Under 1% suggests the kidney is holding on to sodium; over 2% suggests it cannot.
These calculators are free and always will be. We also build Nirogix, a hospital management system for Indian clinics and hospitals. The same calculations are planned inside the consultation record, pre-filled from the chart.