Clearance Rate Calculator

Creatinine clearance is calculated using formulas like Cockcroft-Gault: CrCl = ((140-Age) × Weight) / (72 × Serum Creatinine) × 0.85 (if female). This estimates kidney function by measuring how well kidneys filter creatinine from blood.

Normal creatinine clearance ranges from 90-120 mL/min/1.73m² for healthy adults. Values below 60 mL/min/1.73m² for 3+ months indicate chronic kidney disease. Age, sex, and muscle mass affect normal ranges.

The Chen 2013 equation is considered most accurate for modern populations, while Cockcroft-Gault remains widely used clinically. Chen 2013 accounts for changes in body composition and creatinine generation better than older formulas.

Low creatinine clearance indicates reduced kidney function or kidney disease. Values below 60 mL/min/1.73m² suggest chronic kidney disease, while values below 15 mL/min/1.73m² indicate kidney failure requiring dialysis or transplant.

Kidney function naturally declines with age, typically decreasing by 1 mL/min/1.73m² per year after age 40. All clearance formulas incorporate age as a key factor since muscle mass and kidney function both decrease over time.

Women typically have lower muscle mass than men, resulting in lower baseline creatinine production. Most formulas apply a 0.85 multiplier for females to account for this difference in creatinine generation.

Creatinine clearance estimates kidney filtration rate using creatinine levels, while GFR (glomerular filtration rate) is the actual rate kidneys filter blood. Modern equations estimate GFR more accurately than traditional clearance calculations.

Use mg/dL in the US and µmol/L internationally. The calculator automatically converts between units: 1 mg/dL = 88.4 µmol/L. Always verify which unit your lab uses to ensure accurate calculations.