Creatinine Clearance Calculator

Serum creatinine and the body-weight basis affect the estimate; the formula does not select actual, ideal or adjusted dosing weight. It cannot evaluate acute kidney injury, pregnancy or an individual dosing threshold. Current NIDDK guidance discusses contemporary eGFR equations and body-size adjustment where relevant.

A drug’s specific labeling and the treating team determine the applicable method.

Enter your sex, age, weight and serum creatinine. The Cockcroft-Gault equation, published in 1976, estimates creatinine clearance in milliliters per minute from age, weight and creatinine, with a 15% reduction for women. Pharmacists and clinicians often use it to adjust the doses of drugs cleared by the kidneys, because many drug labels use it.

Use the weight basis specified for the clinical application. Actual, ideal and adjusted weight can produce different Cockcroft–Gault estimates; this calculator does not select a dosing protocol.

Estimated creatinine clearance (mL/min) from sex

Sex	Male
Age	45.0 years
Weight	170
Serum creatinine	1
Estimated creatinine clearance (mL/min)	101.7

Creatinine Clearance: formula

Cockcroft-Gault: CrCl = (140 − age) × weight (kg) ÷ (72 × serum creatinine); × 0.85 if female

NIDDK: Estimating Glomerular Filtration Rate · NIDDK: Kidney estimates and drug dosing

Common error: Treating a Cockcroft-Gault result and an eGFR result as interchangeable numbers that should match. They estimate related but distinct measures of kidney function, built for different original purposes, and a gap between them is expected, not a sign either calculation is wrong.

Creatinine Clearance: changing Age

Estimated creatinine clearance (mL/min): assumed Age scenarios.
Age	Estimated creatinine clearance (mL/min)
23.0 years	125.3
34.0 years	113.5
45.0 years (example)	101.7
56.0 years	90
67.0 years	78.2

Creatinine Clearance: compare input ranges

Creatinine Clearance Calculator: Estimated creatinine clearance (mL/min) with each input moved on its own, every other input held at the worked-example value.
Input	Tested from	To	Estimated creatinine clearance (mL/min): low input	Estimated creatinine clearance (mL/min): high input	Swing
Age	34.0 years	56.0 years	113.5	90	23.6 (23%)
Serum creatinine	0.9	1.1	113	92.5	20.6 (20%)
Weight	153	187	91.6	111.9	20.3 (20%)
Sex	Male	Female	101.7	86.5	15.3 (15%)

Creatinine Clearance: individual input comparisons

Creatinine Clearance Calculator: change one input at a time; other values remain at the stated example.
Input	Value	Estimated creatinine clearance (mL/min)
Sex	Male	101.7
Sex	Female	86.5
Age	23.0 years	125.3
	34.0 years	113.5
	45.0 years	101.7
	56.0 years	90
	67.0 years	78.2
Weight	136	81.4
	153	91.6
	170	101.7
	187	111.9
	204	122.1
Serum creatinine	0.8	127.2
	0.9	113
	1	101.7
	1.1	92.5
	1.2	84.8

Estimated creatinine clearance (mL/min): Age against Weight

Creatinine Clearance: Estimated creatinine clearance (mL/min) at combined Age and Weight settings.
Age / Weight	136	170	204
23.0 years	100.2	125.3	150.4
34.0 years	90.8	113.5	136.2
45.0 years	81.4	101.7	122.1
56.0 years	72	90	108
67.0 years	62.5	78.2	93.8

Creatinine Clearance: values and definitions

Worked-example inputs and the results they produce for the Creatinine Clearance Calculator.
Quantity and definition	Value used
Sex — The Cockcroft-Gault equation applies a correction factor for women.	Male
Age — Age in years.	45.0 years
Weight — Body weight in pounds.	170
Serum creatinine — From a recent blood test, in mg/dL.	1
Estimated creatinine clearance (mL/min)	101.7

Age: half and double

Creatinine Clearance scale comparison; assumed inputs.
Age	Estimated creatinine clearance (mL/min)
22.5 years	125.8
45.0 years	101.7
90.0 years	53.5

Cockcroft-Gault and CKD-EPI both estimate kidney function from a blood creatinine value, and they were built for different purposes decades apart. Cockcroft-Gault was developed for drug-dosing decisions, while CKD-EPI was developed later specifically to grade chronic kidney disease. The two can return meaningfully different numbers for the identical person, and neither one is simply a more accurate version of the other.

Read this alongside an eGFR result rather than in place of it, and note which equation any specific dosing guidance or lab report specifies before comparing values across them.

Compare with the GFR calculator, and see the body surface area, BMI and ideal weight pages for size measures used in dosing. A pharmacist can explain how kidney function affects your medicines. Get repeat labs if your health changes.

How is it different from eGFR?

eGFR uses standardized equations to stage kidney disease and is indexed to body size, while Cockcroft-Gault estimates clearance in milliliters per minute from weight.

Can I use this to change my medication dose?

No. Only a prescriber or pharmacist should adjust a dose, using your lab results and clinical situation.

Why is Cockcroft-Gault still used?

Many drug labels and dosing guidelines were built on it, so pharmacists continue to use it to adjust doses for kidney function.

Creatinine Clearance Calculator