1Patient values
Use a stable serum creatinine. Height is optional — with it, ideal and adjusted body weight are worked out as well.
years
kg
cm
2Creatinine clearance
—
Enter sex, age, weight and creatinine.
Formula & evidence
Formula
CrCl (mL/min) = (140 − age) × weight (kg) / (72 × serum creatinine (mg/dL))
× 0.85 if female
Creatinine µmol/L ÷ 88.4 = mg/dL
Which weight
- Without height, actual body weight is used — the equation as published.
- With height: BMI under 18.5 uses actual weight, 18.5 to 24.9 uses ideal weight, 25 and over uses adjusted weight. All three results are always shown.
- Ideal weight (Devine): male 50 kg, female 45.5 kg, plus 2.3 kg for each inch over 60 inches. Adjusted weight = ideal + 0.4 × (actual − ideal).
- If ideal weight is not below actual weight, actual weight is used. Below 152.4 cm the Devine formula is extrapolated and the result is flagged.
Read with care
- This is creatinine clearance in mL/min. It is not indexed to body surface area and is not the same quantity as eGFR.
- It assumes stable renal function. It is unreliable in acute kidney injury or when creatinine is changing quickly.
- The equation was derived in adult men; “15% less in females” is the authors’ adjustment.
- A low creatinine is not rounded up — rounding did not improve accuracy (Winter 2012).
- Product labels state which weight their dosing studies used. Follow the label.
References
Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine.
Nephron 1976;16(1):31–41.
doi:10.1159/000180580
Winter MA, Guhr KN, Berg GM. Impact of various body weights and serum creatinine
concentrations on the bias and accuracy of the Cockcroft-Gault equation.
Pharmacotherapy 2012;32(7):604–12.
doi:10.1002/j.1875-9114.2012.01098.x