Creatinine Clearance Calculator

About this calculator

This calculator estimates creatinine clearance (CrCl), a measure of kidney filtering function, using the Cockcroft-Gault formula: CrCl = [(140 − age) × weight(kg) × (0.85 if female)] ÷ (72 × serum creatinine mg/dL). It approximates the glomerular filtration rate by relating how quickly the kidneys clear creatinine — a waste product from muscle metabolism — from the blood, adjusted for age, sex, and body weight since muscle mass (and thus baseline creatinine production) varies by these factors.

Physicians and hospital pharmacists rely on Cockcroft-Gault primarily for renal drug dosing — many medications (including common antibiotics, anticoagulants, and chemotherapy agents) must be dose-adjusted based on kidney function to avoid toxic accumulation, and this formula remains the historical reference standard baked into most drug-label dosing tables, even though newer eGFR equations (like CKD-EPI) are now preferred for general kidney-disease staging. Enter age, weight, sex, and serum creatinine to estimate CrCl.