Creatinine Clearance Calculator
Creatinine clearance is a key indicator of kidney function used to stage chronic kidney disease and adjust medication dosages. This calculator uses the Cockcroft-Gault equation, one of the most widely used formulas in clinical practice, to estimate your kidney function from a blood test result.
The Cockcroft-Gault equation estimates creatinine clearance (CrCl) as a surrogate for glomerular filtration rate (GFR), which measures how effectively the kidneys filter waste from the blood. The formula accounts for age (kidney function naturally declines with age), body weight (larger bodies produce more creatinine), sex (women produce less creatinine due to lower muscle mass), and serum creatinine levels.
The formula is: CrCl = [(140 - age) x weight(kg)] / [72 x serum creatinine(mg/dL)], multiplied by 0.85 for women. Normal creatinine clearance is approximately 90-120 mL/min for young adults and decreases by about 1 mL/min per year after age 40.
Creatinine clearance is used clinically for two primary purposes: staging chronic kidney disease (CKD) and adjusting medication dosages. Many drugs are cleared by the kidneys, and impaired kidney function leads to drug accumulation and potential toxicity. This is why drug prescribing information often includes dose adjustments based on CrCl. This calculator is for educational purposes only and should not replace professional medical evaluation.