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Adult Creatinine Clearance (CrCl) Calculator

Change all to SI units?:

Age: years    (if < 18 yrs use Peds Calculator)


Creatinine Clearance (CrCl):
Creatinine Clearance (per IBW):
Creatinine Clearance (per ABW):

Other Results

Body Mass Index (BMI):
Total Body Wt (TBW):
Ideal Body Wt (IBW):
Lean Body Wt (LBW):
Adjusted Body Wt (ABW):
Percent Under/Over (IBW):
Body Surface Area (BSA):
using Boyd formula
using DuBois formula
using Gehan & George formula
using Haycock formula
using Mosteller formula

Assumptions for the use of this Adult Creatinine Clearance (CrCl) Calculator
  • The patient is > 18 years of age 
  • The renal function is considered stable (i.e., not in acute renal failure)
Formulas Used:
  • Adult Males = [(140 - age in years) x (weight in kg)] ÷ 72 x serum Cr
  • Adult Females = 0.85 x [((140 - age in years) x (weight in kg)) ÷ 72 x serum Cr]

The Normal or Maximum CrCl:
The estimated creatinine clearance (CrCl) is not normally physiologically greater than 120 ml/min for most adults. As such, this calculator reports a max result of 120 ml/min to avoid potential inappropriate interpretations of the estimated CrCl.

The Elderly and/or Underweight Patient:
In patients who are older than 65 years of age, and/or who are underweight, and have a serum creatinine < 0.8 mg/dL, some literature supports that adjustment of the creatinine up to at least 0.8 to 1.0 mg/dL to avoid overestimating the CrCl in the elderly. Since there is no formal consensus among clinicians of various specialities on which to use and in what type of patient, the calculator allows the clinician to enter in the values as they feel are appropriate given the medical scenario. When in doubt, a 24 hour creatinine clearance should be given consideration.

The Overweight or Obese Patient:
Some clinicians will make adjustments based on the actual weight of the patient in relation that patient's ideal body weight (IBW) and/or adjusted body weight (ABW), especially if their actual body weight is greater than 20% over the IBW. Failing to consider the actual weight of the patient could also grossly overestimate the CrCl. As such, the calculator automatically provides those additional values for consideration if the situation warrants that.  Lastly, it is important to keep in mind that the Cockcroft Gault equation is merely an estimation of the CrCl and not an absolute number.

Staging for Chronic Kidney Disease (CKD):
It is also important to note that currently the staging of chronic kidney disease (CKD) is based on the estimated GFR not the CrCl. To calculate the eGFR click here To calculate all estimated values for assessing renal function, visit the Comprehensive Renal Function Calculator.

For information and supporting references regarding the BMI, BSA, and weights please click here


Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron 1976;16(1):31-41. PubMed