Creatinine Clearance (CrCl) Calculator
Uses the Cockcroft-Gault equation. This is the mandatory standard for adjusting renally cleared drugs (including DOACs) in the UK, as eGFR often overestimates clearance in the elderly or underweight.
Results
mL/min
Ideal Body Weight (IBW): kg
CrCl using IBW: mL/min
*If Actual Weight > 20% above IBW, consider using Adjusted Body Weight or IBW depending on local formulary guidance for specific drugs.
Clinical Notes
The Cockcroft-Gault equation remains the gold standard for adjusting drug dosages in renal impairment. Unlike eGFR (MDRD or CKD-EPI), which is normalised to a body surface area of 1.73m², Cockcroft-Gault estimates absolute clearance.
- DOACs: Apixaban, Rivaroxaban, Edoxaban, and Dabigatran must be dosed using CrCl, not eGFR.
- Low Muscle Mass: In elderly or malnourished patients with very low serum creatinine (<60 µmol/L), some local guidelines recommend rounding the SCr up to 60 µmol/L to avoid overestimating renal function. This calculator does not automatically do this.
- Obesity: For patients weighing >20% above their Ideal Body Weight, the standard CG equation may overestimate clearance. Consult local guidelines on whether to use Adjusted Body Weight.
Formula Used
CrCl =
(140 - Age) × Weight × Constant
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Serum Creatinine (µmol/L)
(140 - Age) × Weight × Constant
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Serum Creatinine (µmol/L)
- Constant (Male): 1.23
- Constant (Female): 1.04
- IBW (Male): 50 + 2.3 × (Height(in) - 60)
- IBW (Female): 45.5 + 2.3 × (Height(in) - 60)