This analysis reviewed various methods of calculating estimated glomerular filtration rate (GFR) in patients with a BMI >30kg/m2 and compared against measured GFR (by plasma clearance measurement of creatinine-EDTA injection). Equation calculations compared to the measured GFR included the Chronic Kidney Disease Epidemiology Collaboration equation, the MDRD equation de-indexed by body surface area, and the Cockroft and Gault equation using adjusted body weight, adjusted ideal body weight and lean body weight.