Do you have more mass than your heart can handle? The body mass index calculator will tell you. Medical researchers searched for an accurate, uniform way to measure fatness for decades when in 1972, physiology professor and obesity researcher Ancel Keys published his “Indices of Relative Weight and Obesity,” a landmark study of more than 7,400 men in five countries. Keys considered the various height-weight formulas in existance and found Quetelet’s equation to be the best marker of body-fat percentage. He renamed this number the body mass index or BMI. As Singer-Vine reports, the new number caught on among researchers who had previously relied on slower and more expensive measures of body fat or on the broad and ambiguous categories defined by the insurance companies.