Creatinine Clearance Calculator

Creatinine clearance estimates how much plasma the kidneys clear of creatinine each minute. Creatinine is produced during normal muscle metabolism and is removed mainly through glomerular filtration. When filtration falls, serum creatinine generally rises. A concentration alone can be difficult to interpret because age, body size, sex, muscle mass, diet, hydration, and some medicines affect creatinine production or handling. Equations combine several of those variables to provide more useful kidney function estimates. The Cockcroft-Gault equation calculates creatinine clearance in milliliters per minute from age, body weight, serum creatinine, and sex. It subtracts age from 140, multiplies by weight in kilograms, divides by 72 times creatinine in mg/dL, and applies a factor of 0.85 for females. Many medication labels and dosing references still use this estimate. The appropriate weight may be actual, ideal, or adjusted weight depending on body composition and local clinical protocol; this calculator uses the entered weight without making that choice for the user. MDRD and CKD-EPI estimate glomerular filtration rate normalized to a body surface area of 1.73 square meters. Their units and intended uses therefore differ from unindexed Cockcroft-Gault clearance. This tool uses the 2021 creatinine-only CKD-EPI equation, which does not include a race coefficient. The optional legacy race field remains visible to reflect the source calculator but does not alter either modern result. Height is similarly retained for context but is not needed by the displayed equations. No estimated equation directly measures filtration. Results may be unreliable during rapidly changing kidney function, acute kidney injury, pregnancy, dialysis, unusual muscle mass, amputation, severe malnutrition, or creatine supplementation. A stable, standardized laboratory creatinine is preferable. Cystatin C or measured clearance may be considered when greater accuracy is needed. Chronic kidney disease is not diagnosed from one low estimate alone; duration, urine albumin, imaging, and other evidence matter. Medication doses must not be changed solely from this page. A pharmacist or prescriber should select the equation, weight convention, dose interval, and monitoring plan required by a specific medicine. Discuss unexpectedly reduced or changing results with a clinician, especially when accompanied by swelling, reduced urine, shortness of breath, confusion, vomiting, or acute illness.