Creatinine Clearance (Cockcroft-Gault)

yr
kg
mg/dL
Health

Estimate creatinine clearance (CrCl) and kidney function using the Cockcroft-Gault formula.

Formula

CrCl = (140 − age) × weight (kg) / (72 × SCr mg/dL) × 0.85 [females only]
  • Weight: use actual body weight for underweight/normal patients; ideal body weight + 40% of excess for obese patients.
  • Females: multiply result by 0.85 (lower muscle mass).
  • Use for drug dosing adjustments (e.g. renally-cleared antibiotics, anticoagulants, chemotherapy).
  • Not equivalent to MDRD or CKD-EPI eGFR — CG is preferred for drug dosing.

65-year-old female, 65 kg, SCr 1.2 mg/dL

Inputs
  • Age: 65 yr
  • Actual Body Weight: 65 kg
  • Serum Creatinine: 1.2 mg/dL
  • Sex: female

CrCl = (140-65)×65/(72×1.2)×0.85 = 4875/86.4×0.85 = 47.97 mL/min.

Frequently asked questions

Why use Cockcroft-Gault instead of eGFR?
Most drug package inserts and clinical studies use CrCl (Cockcroft-Gault) for dosing adjustments. eGFR (MDRD/CKD-EPI) is normalized to BSA=1.73 m² and better for CKD staging.