Clinical calculator

Creatinine Clearance by Cockcroft-Gault, Age 16 Years or Older

A browser-only educational calculator for Cockcroft-Gault estimated creatinine clearance in adults and older adolescents. Information entered on this page is not saved or stored by RPHprep.

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Cockcroft-Gault inputs

Equation

Estimated_creatinine_clearance = Sex * ((140 - Age) / Serum_creatinine) * (Weight / 72)

SI option = Sex * (1.2 * (140 - Age) * Weight) / Serum_creatinine_umol_L

Sex
Serum creatinine unit

Calculation details and notes

Equation parameters such as sex use discrete calculator values. The number shown next to each option is the factor used in the equation.

The Cockcroft-Gault equation was developed before standardized creatinine assays and has been replaced by more accurate methods for evaluating GFR and staging kidney disease.

Cockcroft-Gault creatinine clearance estimates remain visible in some drug-dosing sources, including older regulatory labels. Contemporary kidney-function estimation methods may be preferred in current practice and should be checked against current references.

eGFR values calculated using MDRD or CKD-EPI equations should not be used interchangeably with Cockcroft-Gault creatinine clearance values for drug dosage calculation or adjustment. Renal function should be estimated using the equation on which the dosage-adjustment guidance was based.

Weight adjustments such as adjusted body weight, ideal body weight, or lean body weight have been proposed for some body-size contexts, but their use is not standardized or universally accepted.

References

  1. Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976;16(1):31-41. Source
  2. KDIGO CKD Work Group. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int. 2024;105(4S):S117-S314. Source
  3. St Peter WL, Bzowyckyj AS, Anderson-Haag T, et al. Moving forward from Cockcroft-Gault creatinine clearance to race-free estimated glomerular filtration rate. Am J Health Syst Pharm. 2025;82(12):644-659. Source
  4. National Institute of Diabetes and Digestive and Kidney Diseases. Determining drug dosing in adults with chronic kidney disease. Source
  5. National Kidney Foundation. Cockcroft-Gault formula. Source
  6. US Food and Drug Administration. Pharmacokinetics in patients with impaired renal function: study design, data analysis, and impact on dosing. Published March 15, 2024. Source