Creatinine Clearance Calculator
Cockcroft-Gault creatinine clearance in mL/min from age, weight in kg or lb, serum creatinine in mg/dL or µmol/L, and sex. An estimate, not a lab result. How it works
Use the Creatinine Clearance Calculator
About the Creatinine Clearance Calculator
A 45-year-old man weighing 75 kg with a serum creatinine of 1.0 mg/dL has an estimated creatinine clearance of 99 mL/min: (140 − age) × weight in kg ÷ (72 × creatinine), multiplied by 0.85 for a woman, who gets 84.1 mL/min with the same values. This is the Cockcroft-Gault equation from 1976. It is an estimate from one blood result and actual body weight, not a measured clearance and not a basis for changing a medicine dose.
Estimated CrCl for a 70 kg man, in mL/min
| Age | 0.8 mg/dL (70.7 µmol/L) | 1.0 mg/dL (88.4 µmol/L) | 1.5 mg/dL (132.6 µmol/L) | 2.0 mg/dL (176.8 µmol/L) | 3.0 mg/dL (265.2 µmol/L) |
|---|---|---|---|---|---|
| 30 years | 133.7 | 106.9 | 71.3 | 53.5 | 35.6 |
| 45 years | 115.5 | 92.4 | 61.6 | 46.2 | 30.8 |
| 60 years | 97.2 | 77.8 | 51.9 | 38.9 | 25.9 |
| 75 years | 79 | 63.2 | 42.1 | 31.6 | 21.1 |
| 90 years | 60.8 | 48.6 | 32.4 | 24.3 | 16.2 |
As the calculator prints them, to 0.1 mL/min. The result is proportional to weight, so 105 kg gives 1.5 times each figure.
Estimated CrCl for a 70 kg woman, in mL/min
| Age | 0.8 mg/dL (70.7 µmol/L) | 1.0 mg/dL (88.4 µmol/L) | 1.5 mg/dL (132.6 µmol/L) | 2.0 mg/dL (176.8 µmol/L) | 3.0 mg/dL (265.2 µmol/L) |
|---|---|---|---|---|---|
| 30 years | 113.6 | 90.9 | 60.6 | 45.5 | 30.3 |
| 45 years | 98.1 | 78.5 | 52.3 | 39.3 | 26.2 |
| 60 years | 82.6 | 66.1 | 44.1 | 33.1 | 22 |
| 75 years | 67.1 | 53.7 | 35.8 | 26.9 | 17.9 |
| 90 years | 51.6 | 41.3 | 27.5 | 20.7 | 13.8 |
The same figures multiplied by 0.85, the equation’s factor for women.
Methodology
CrCl in mL/min = (140 − age in years) × weight in kg ÷ (72 × serum creatinine in mg/dL), multiplied by 0.85 for a woman. A creatinine in µmol/L is divided by 88.4 first. The result prints to 0.1 mL/min with the sum behind it. Weight can be entered in kg or lb; pounds are divided by 2.2046 (165 lb is 74.84 kg). The page accepts ages 18 to 110, weights of 30 to 250 kg (66.1 to 551.2 lb) and creatinine of 0.3 to 15 mg/dL (26.5 to 1,326 µmol/L).
Frequently asked questions
- How do you calculate creatinine clearance?
- With Cockcroft-Gault: subtract the age from 140, multiply by the weight in kg, and divide by 72 times the serum creatinine in mg/dL. Multiply by 0.85 for a woman. A 60-year-old man of 70 kg with a creatinine of 1.5 mg/dL gets 51.9 mL/min.
- Can I enter creatinine in µmol/L?
- Yes. Switch the unit to µmol/L and the page divides by 88.4. 88.4 µmol/L equals 1.0 mg/dL, so the 45-year-old, 75 kg man still gets 99 mL/min. A 70-year-old woman of 60 kg with 133 µmol/L gets 33 mL/min.
- Is creatinine clearance the same as eGFR?
- No. Cockcroft-Gault estimates creatinine clearance in mL/min. The National Kidney Foundation notes that it was validated against measured creatinine clearance, which overestimates GFR, while eGFR equations estimate GFR and are adjusted for body surface area. The NKF now advocates race-free eGFR equations rather than Cockcroft-Gault for adult medication decisions.
- Which weight should I use in Cockcroft-Gault?
- The page uses the weight you enter, as the original equation did. The NKF says using total body weight, or any single weight, lowers its accuracy, especially as average body weight rises. The page has no ideal or adjusted body weight option.
- Can I use this to adjust a medicine dose?
- Not from this page. Doses come from the drug’s labeling, applied by a prescriber or pharmacist. The NKF notes that standardized creatinine assays read about 12% lower than those of the 1970s, so Cockcroft-Gault results today run higher than in the studies that set many dose adjustments.
Related Tools
View all toolsSwim Pace Calculator
Find your swim pace per 100 meters or yards from a distance and total time, plus your speed: 500 m in 10:00 is 2:00 per 100 m and 0.83 m/s.
Target Heart Rate
Target heart rate zones from your age and resting heart rate by the Karvonen method, or as 50 to 85% of maximum heart rate as on the AHA chart.
Fish Tank Nitrogen Cycle Calculator
Enter ammonia, nitrite, nitrate, pH and temperature to see your tank's cycle phase, the free (toxic) ammonia share and a water change suggestion.
VO2 Max Calculator
VO2 max calculator for two field tests: the Cooper 12-minute run distance, or the Rockport 1-mile walk time, heart rate, age, sex and weight, give mL/kg/min.
Weight Loss Plateau Calculator
Weight loss plateau calculator: age, sex, height, weight, activity and daily calories give maintenance, your deficit and a rough, rule-based weeks estimate.
Chocolate Toxicity Calculator for Dogs & Cats
Dog chocolate toxicity calculator: the pet’s weight, the chocolate type and the amount eaten give the theobromine plus caffeine dose in mg/kg. Cats too.