This free software application is to be used to calculate GFR utilizing the MDRD and Gault Methods as well as a 24 hour creatinine clearance from a spot or timed urine. Calculation of GFR can be challenging at times and is not to be confused with creatinine clearance even though the 2 or sometimes used interchangeably. The calculation written in 1976 known as the Cockcroft and Gault method used both serum creatinine and body weight to estimate creatinine clearance. This was followed in 1999 by the 6 variable Modification of Diet in Renal Disease (MDRD) which utilizes a patient's serum creatinine, BUN, albumin as well as age, gender and race to calculate the GFR and the 4 variable in 2000 which only used age, serum creatinine, gender and race. Note that both of these equations do not include patient's weight and are assumed to be standardized to a body surface area of 1.73. From personal experience patients with large body mass tend to have calculated values for Gault and MDRD that very greatly and this can cause a dilemma especially in dosing medications. I have included a version of the MDRD formula's labeled MDRD* which utilizes the patients BSA to correct for differences of body size. Please see the form labeled MDRD* for more information. This GFR calculating software which I wrote utilizes both MDRD formulas as well as one that calculates GFR from age, gender, race, serum creatinine and BUN and a creatinine clearance calculator from a spot (or timed) urine and the amount of urine made in 24 hours. The results are listed as GFR by MDRD, Gault, creatinine clearance, MDRD*, average of these methods, % of GFR expected for age, Stage of CRI, and expected GFR for age. The user can select which methods to be used in his/her calculations for the average GFR with the default values being MDRD and Gault. The software automatically stores your selection choices for further use. As a general rule I always enter the patients' weight to get a value by the Gault-Cockcroft method especially in patients with a BSA that differs greatly from 1.73 square meters. If the patient's height and weight is entered the BSA is displayed on the results form.