Handy ideal body weight calculators are all over the Internet, with instant results that peg you as healthy, too slim or too fat. However, one calculator can say you are underweight while another says you are overweight, even though you appear healthy and lean. What gives? Ideal body weight calculators use different methods to gauge results or omit factors you need to consider.
Methods
Two of the most common ideal weight calculations are the body mass index and the Hamwi formula. Body mass index calculations take height and weight into account while the Hamwi formula uses height and frame size. Other ideal body weight calculations include the Robinson and Miller formulas. Both are revised versions of the Hamwi formula that use slightly different target weights and calculations for additional pounds.
Body Mass Index
Body mass index incorporates only your weight and height to arrive at your estimated percentage of body fat. Healthful amounts of body fat range from 18.5 percent to 24.9 percent of your total weight. Less than 18.5 percent of body fat is considered underweight, 25 percent to 29.9 percent of body fat is deemed overweight and more than 30 percent is obese.
Hamwi Formula
The Hamwi formula uses calculations based on frame size and sex to determine ideal weight. The Hamwi formula puts the ideal weight for a medium frame 5-foot tall man at 106 lbs. and a 5-foot tall woman at 100 lbs. For each additional inch higher than 5 feet, men add 6 lbs. and women add 5 lbs. Men and women with small frames subtract 10 percent from the calculations and those with large frames add 10 percent.
Frame Size
Calculate your frame size by wrapping your thumb and index finger around your wrist. If your fingers touch, you have a small frame. If they barely touch, you have a medium frame and if they are nowhere near touching, you have a large frame. Frame size gives a bit of leeway, but not much, as bones only make up 15 percent of overall body weight.
Other Factors
While ideal weight body calculators offer a general gauge, they do leave out some considerations that play a part in ideal weight. Age, sex and activity all contribute to ideal body weights. Muscle weighs more than fat, so a bodybuilder or muscular, active person will weigh more than a sedentary person of the same height and frame size. Other people, especially older adults, have a low muscle mass, which would decrease their ideal target weight. The distribution of fat is also ignored, which according to the Mayo Clinic could affect those with excess abdominal fat by not accurately noting their health risks.
Member Comments