CrCl Calculator

Variables and formulas

Serum creatinine is a laboratory determination that is easy to obtain through a blood test. This can be then input in the Jelliffe equation to retrieve the creatinine clearance rate which is an indicator of renal function. The formula also accounts for patient age, gender, height and weight.

The above calculator is flexible in terms of the measurement system used and accepts both English and Metric determinations. Serum creatinine can be input in either mg/dL or µmol/L.

The CrCl calculator also displays other indicators of body health:

■ Body surface area (used in the CrCl equation);

■ Body mass index;

■ Ideal body weight;

■ Lean body mass.

The estimated creatinine clearance rate (eCCr) based on the 1973 equation by Jelliffe is:

eCCr = {[98 – 0.8 x (Age – 20)] x [1 – (0.1 x Gender)] x (BSA/1.73)} / (Serum creatinine in µmol/L x 0.0113)

Where:

■ Gender value is 0 for men and 1 for women.

■ BSA is calculated via Boyd’s, DuBois’s, Gehan & George’s, Haycock’s or Mosteller’s formula.

■ Serum creatinine is expressed in µmol/L. In case the serum creatinine is given in mg/dL, the conversion from mg/dL to µmol/L is: 1 mg/dL = 88.4 µmol/L.

The following table introduces the various formulas used to determine body surface area:

Creatinine clearance guidelines

Serum creatinine (measured in either mg/dL or µmol/L) is a component found in muscles and that is metabolised through kidney filtration. Normal serum creatinine ranges between 0.6 and 1.3 mg/dL, with some gender specific variation, because women tend to have less muscle mass than men.

The rate of creatinine clearance offers an accurate estimation of the filtration function of the renal system. This is measured in milliliters/ minute (ml/min) and normal values are around 98-136 ml/min in men and 88-128 mL/min in women.

If the renal filtration function or glomerular filtration rate (GFR) is impaired, serum creatinine levels increase.

Any CrCl value above 130 mL/min may be indicative of some kind of renal dysfunction, either of filtration, existence of infection, reduced blood flow, dehydration or muscular problems.

Original source

Jelliffe R. Letter: Creatinine clearance: bedside estimate. Ann Intern Med. 1973; 79(4):604-5.

Other references

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

2. Gault MH, Longerich LL, Harnett JD, Wesolowski C. Predicting glomerular function from adjusted serum creatinine. Nephron. 1992; 62 (3): 249–56.

3. DuBois D, DuBois DF. A formula to estimate the approximate surface area if height and weight be known. Arch Int Med 1916; 17:863-71.

4. Diamandopoulos A, Goudas P, Arvanitis A. Comparison of estimated creatinine clearance among five formulae (Cockroft–Gault, Jelliffe, Sanaka, simplified 4-variable MDRD and DAF) and the 24hours-urine-collection creatinine clearance. Hippokratia. 2010; 14(2): 98–104.

5. Jelliffe R. Estimation of creatinine clearance in patients with unstable renal function, without a urine specimen. Am J Nephrol. 2002; 22(4):320-4.