Creatinine Clearance Calculator
Estimate creatinine clearance for renal drug dosing using the Cockcroft-Gault equation.
Actual body weight, as used in the original 1976 study.
For obese patients, many clinicians substitute ideal or adjusted body weight for actual weight — ask a pharmacist or clinician which weight to use for a specific drug dosing decision.
Cockcroft-Gault estimates creatinine clearance, which is what most drug package inserts use for renal dosing adjustments. It is a different estimate from eGFR (CKD-EPI), which is used for staging chronic kidney disease — the two can give different numbers for the same patient.
Not a dosing recommendation. This estimate is for informational and educational purposes only. Renal drug dosing depends on the specific medication, indication, and patient factors that only a pharmacist or prescriber can evaluate.
How creatinine clearance is calculated
Cockcroft-Gault (1976)
Published by Cockcroft and Gault in 1976, this equation predates modern standardized creatinine assays but remains the reference equation cited in most drug package inserts for renal dosing. It differs from the CKD-EPI equation used by CalcuOnline's eGFR Calculator — the two serve different purposes and can produce different numbers for the same patient.
Common questions
Creatinine clearance approximates how much blood the kidneys clear of creatinine per minute. It’s the estimate most commonly referenced in drug labeling for renal dose adjustments, so it’s widely used by pharmacists and prescribers when dosing renally cleared medications.