Creatinine Clearance Calculator

Evaluates renal function via the Cockcroft Gault equation based on creatinine, patient age, weight and height.

There is more information about the calculation method in the text below the form.

Creatinine clearance is a derivative calculation based on serum creatinine which can offer information on the filtration function of the kidneys.

Serum creatinine is obtained via a specialized blood test whilst the other variables, are easily identifiable (age, gender, weight and height).

Part of the calculation, the ideal body weight (via Devine formula) is also identified and provided.

The Cockcroft and Gault equation is:

CrCl for men = [(140 - age) x Weight in kg] / (Serum Creatinine in mg/dL x 72)

CrCl for women = [(140 - age) x Weight in kg x 0.85] / (Serum Creatinine in mg/dL x 72)

Devine’s formula for ideal body weight is also gender specific:

IBW men = 50 kg + (2.3 x (Height in inches - 60))

IBW women = 45.5 kg + (2.3 x (Height in inches - 60))

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Steps on how to print your input & results:

1. Fill in the calculator/tool with your values and/or your answer choices and press Calculate.

2. Then you can click on the Print button to open a PDF in a separate window with the inputs and results. You can further save the PDF or print it.

Please note that once you have closed the PDF you need to click on the Calculate button before you try opening it again, otherwise the input and/or results may not appear in the pdf.

CrCl explained

Creatinine clearance is one of the renal indicators of the kidney filtration rate. The most common method to determine it is via the Cockcroft Gault equation.

The above calculator requires the patient’s gender, age, height and weight and the serum creatinine. The formulas used are gender specific:

CrCl for men = [(140 - age) x Weight in kg] / (Serum Creatinine in mg/dL x 72)

CrCl for women = [(140 - age) x Weight in kg x 0.85] / (Serum Creatinine in mg/dL x 72)

These can be adapted for use when serum creatinine is expressed in µmol/L:

CrCl for men = [(140 - age) x Weight in kilograms x 1.23] / (Serum Creatinine in µmol/L)

CrCl for women = [(140 - age) x Weight in kilograms x 1.04] / (Serum Creatinine in µmol/L)

The calculation of the ideal body weight takes place via the Devine formula:

Male = 50 kg + (2.3 x (Height in inches - 60))

Female = 45.5 kg + (2.3 x (Height in inches - 60))

About the study

The above formulas have been devised by Cockcroft and Gault in 1976 to predict creatinine clearance in a cohort of 249 patients aged 18 to 92. During derivation, a relationship was observed between the age of the subject and 24-hour creatinine excretion/kg.

Values for creatinine clearance were predicted through several methods and then compared with the 24-hour determinations in the case of 236 patients from the cohort.

The formulas gave a correlation coefficient between predicted and mean measured creatinine clearance of 0.83, on average.

Creatinine guidelines

Creatinine is the breakdown product of muscular creatine. Once the latter is metabolised, it is cleared through the kidneys and this rate is considered to be an accurate indicator of the renal filtration function.

If the kidneys don’t filter creatinine, the blood levels (serum creatinine) rise. SCr is measured in mL/min and normal values are of 98 to 136 mL/min in men and 88 to 128 mL/min in women.

However, even low levels may suggest some kind of damage to the kidneys (renal failure) or some other kind of circulatory obstruction.

Other recent calculations are starting to replace the classic creatinine clearance determination for patients with chronic kidney disease, such as the MDRD (Modification of Diet in Renal Disease). However, MDRD is yet to be validated in acute renal failure.