You may want to look like the supermodel on the cover of your favorite fashion magazine, but you might not be built quite the same way. Measuring your wrist to determine your body frame size can help you develop ideal expectations of a healthy weight specific for your height and build. If you're concerned about your weight as it relates to your body frame, consult a doctor to discuss how it might affect your health.
Measuring Your Wrist With a Tape Measure
Body frame size can be determined measuring your wrist with a tape measure and comparing it to your height. Place the tape around your wrist in the same area you wear a watch -- above the ball joint of your ulna -- to determine the circumference of your wrist in inches.
Once you know your wrist size, compare it to your height to determine body frame size. For women 5 foot, 2 inches to 5 foot, 5 inches tall, a wrist size of 6 inches or less is considered small framed, 6 to 6.25 inches is medium framed, and 6.25 inches or greater is large framed. For women taller than 5 foot, 5 inches, less than 6.25 inches is considered small framed, 6.25 to 6.5 inches medium framed, and greater than 6.5 inches large framed.
For men, a wrist size measuring 5.5 to 6.4 inches is considered small framed, 6.5 to 7.5 is a medium frame, and greater than 7.5 inches is a large frame size.
Measuring Your Wrist With Your Fingers
While the measuring tape method may be the most accurate way to determine body frame size, you can also use your thumb and index finger to estimate your frame size. Wrap your thumb and forefinger around your wrist in the area you normally wear a watch. If your fingers overlap, you are considered small framed; if your fingers touch tip to tip, you're medium framed; and if you see a space between your thumb and index finger, you have a large frame.
Now That You Know Your Body Frame Size
Once you know your body frame size, you can use it to determine your ideal body weight. The HAMWI method is a simple calculation that you can use to estimate your weight and adjust based on your body frame size. The equations calculate the IBW for medium-framed people; then you add or subtract 10 percent for small or large frames.
For women, start at 100 pounds and add 5 pounds for every inch above 5 feet. For men, start with 106 pounds and add 6 pounds for every inch above 5 feet.
For example, the IBW for a 6-foot tall, medium-framed man is 106 + (12 x 6) = 178 pounds. The IBW for a small-framed man is 10 percent less than 178, or 160 pounds, and the IBW for a large-framed man is 10 percent great than 178, or 196 pounds. So, for healthy men who are 6 feet tall, the IBW range is 160 to 196 pounds, depending on their body frame sizes.
BMI Versus IBW
While your IBW may help you determine the number you should shoot for when you step on the scale, it may not be the best way to determine good health as to your weight. Body mass index estimates body composition and is better at determining health risk than IBW.
Like ideal body weight, a mathematical formula is used to estimate BMI; all you need is your height and weight. Divide your weight in pounds by your height in inches squared and multiply by 703.
BMI = [weight / (height x height)] x 703.
If you're 6 feet tall and weigh 196 pounds, your BMI is 26.5, which places you in the overweight category on the BMI chart, even though 196 is considered an ideal weight for a large-framed man of this height. If you need help interpreting your IBW or BMI, check with your doctor or a dietitian for clarification.