Cockcroft–Gault Creatinine Clearance
Provide patient age, weight, sex, and serum creatinine to estimate creatinine clearance (CrCl) for drug dosing and renal function assessment.
Use actual body weight. For obesity, consider adjusted body weight per institutional policy.
Height in centimetres. Used to calculate body surface area and indexed clearance.
How to Use This Calculator
Collect patient demographics and labs
Use patient age (years), sex, weight, and most recent serum creatinine concentration. Height is optional but helpful for indexing to BSA.
Enter values with correct units
Switch between mg/dL and µmol/L for creatinine or kg and lb for weight. The calculator converts automatically.
Interpret clearance for dosing and staging
Use CrCl to adjust renally cleared medications, stage CKD, and determine need for nephrology referral. Confirm with eGFR when available.
Formula
Cockcroft–Gault = ((140 − Age) × Weight (kg)) ÷ (72 × Serum Cr (mg/dL))
Multiply by 0.85 for females.
BSA adjustment (optional) = CrCl × (1.73 ÷ BSA)
Full Description
The Cockcroft–Gault equation estimates creatinine clearance based on age, weight, sex, and serum creatinine. It is widely used for drug dosing and renal function screening, though MDRD or CKD-EPI equations may better estimate GFR for staging CKD. Adjust weight inputs per institutional policy: actual body weight works for most patients, but consider adjusted body weight in obesity and ideal body weight in underweight individuals. Always correlate with clinical context, urine output, and eGFR trends.
Frequently Asked Questions
Which weight should I use in obesity?
Guidelines vary. Consider using adjusted body weight (IBW + 0.4 × (actual − IBW)) for BMI ≥30 kg/m², but follow institutional dosing policies.
Can I use this calculator for dialysis patients?
Creatinine clearance equations are unreliable in dialysis or rapidly changing renal function. Use measured clearance or consult nephrology.
How does this differ from eGFR?
eGFR (CKD-EPI/MDRD) normalises to 1.73 m² BSA and is recommended for CKD staging. Cockcroft–Gault is traditionally used for medication dosing.
Should I round serum creatinine in elderly patients?
Avoid arbitrary rounding. Use measured serum creatinine and clinical judgement; rounding may underestimate renal function and lead to underdosing.