Creatinine Clearance Calculator
Estimate creatinine clearance with the Cockcroft-Gault formula. Supports actual, ideal (Devine), and adjusted body weight, plus mg/dL and umol/L creatinine.
Cockcroft-Gault Weight Options
The calculator can apply actual, ideal, or adjusted body weight before estimating creatinine clearance.
| Weight option | Example value | Formula use | When selected |
|---|---|---|---|
| Actual body weight | 100 kg | Directly in equation | Actual option |
| Ideal body weight | 70 kg | Directly in equation | Ideal option |
| Adjusted body weight | 82 kg from 100 kg actual and 70 kg IBW | IBW + 0.4 × excess | BMI above 30 |
Frequently Asked Questions about the Creatinine Clearance Calculator
What formula does this calculator use?
The Cockcroft-Gault equation from 1976: CrCl (mL/min) = ((140 - age) x weight_kg x sex_factor) / (72 x serum_creatinine_mg_dL), where the sex factor is 1.00 for men and 0.85 for women. Many drug package inserts still anchor their dose adjustments to Cockcroft-Gault.
Should I use actual, ideal, or adjusted body weight?
The weight choice is protocol-dependent. Actual body weight is often used when body size is not extreme, while some drug-dosing protocols use adjusted or lean weight in obesity. Ideal body weight is not a general rule for an underweight patient. Follow the medication's labeling or your pharmacy protocol, because the selected weight can materially change Cockcroft-Gault clearance.
Why does this calculator also show a BSA-normalized result?
Cockcroft-Gault reports raw mL/min, while CKD-EPI eGFR reports mL/min per 1.73 m^2. When you enter a height, this calculator also shows a BSA-normalized creatinine-clearance estimate. Neither result diagnoses chronic kidney disease or assigns a CKD stage from one measurement. A clinician interprets trends, duration, urine findings, and the clinical context.
How do I convert creatinine from umol/L to mg/dL?
Divide umol/L by 88.4 to get mg/dL. So 88.4 umol/L equals 1.0 mg/dL. The 88.4 factor comes from creatinine's molecular weight (113.12 g/mol) and dL-to-L conversion. Most countries outside the US report creatinine in umol/L.
Is this a medical diagnosis?
No. This is a screening estimate. Cockcroft-Gault was derived in a small, hospitalized, mostly male population and is known to overestimate kidney function in obese, edematous, or sarcopenic patients and underestimate it in muscular ones. Use the result only as a conversation starter with your clinician.
Related Calculators
More calculators in "Health"
ASCVD Risk CalculatorCholesterol Ratio CalculatorQTc CalculatorTreadmill Pace CalculatorTarget Heart Rate CalculatorIV Drip Rate Calculator
See all 103 calculators in "Health"