How to Measure Your Wrist to Get Your Body Frame Size — and What It Can Tell You About Your Ideal Weight

All you have to do is look to the world of sports to see that there's no one "right" body size. From jockeys to basketball players to sumo wrestlers, bodies come in all different (and equally beautiful) shapes and sizes.

While it's never a good idea to compare your body to someone else's — we're all so unique, after all — knowing your general body frame size ‌may‌ help you set realistic expectations when it comes to your weight and fitness goals.

Keep in mind that there's no such thing as an "ideal body weight," (even though the medical field still uses ideal body weight and BMI as a health determinant) and body frame size can vary greatly based on an individual's calorie needs, physical activity, genetics, metabolism, etc.

This is not an ideal way to measure your body frame, as everyone's wrist size is different no matter what their body size is. However, some people still measure their wrist with a tape measure to determine their frame, according to the U.S. National Library of Medicine.

With this method, once wrist size is determined, body frame is divided into small-, medium- or large-boned categories.

(Note: The following charts use terms like "AFAB" [assigned female at birth] and "AMAB" [assigned male at birth], however, body frame is not exclusively determined by gender. There are many determinants for body size, such as genetics, metabolism, physical activity level and more.)

Although using a tape measure is considered the more accurate way to determine body frame size, you can also use your thumb and index finger. With this method, the space between your fingers determines your small, medium or large body frame.

The short answer? No. As mentioned above, there is no such thing as an "ideal body weight," however, some medical professionals still use ideal body weight in the form of a measurement tool with their patients.

There are several formulas you can use to determine your ideal body weight (IBW), according to a May 2016 article in ‌The American Journal of Clinical Nutrition.‌ The HAMWI method is a simple calculation used to estimate weight and is adjusted based on body frame size. The equations below calculate the IBW for medium-framed people; then 10 percent is added or subtracted depending on "small" or "large" frames.

(Note: The following measurements use "AFAB" and "AMAB," but body size is not necessarily dependent on gender.)

‌For people AFAB, start at 100 pounds and add 5 pounds for every inch above 5 feet:‌

IBW (lb) = 100 + 5 x (Ht – 60 in)

‌For people AMAB, start with 106 pounds and add 6 pounds for every inch above 5 feet:‌

IBW (lb) = 106 + 6 x (Ht – 60 in)

So, for example, the IBW for a 6-foot tall, medium-framed person AMAB is:

106 + 6 x (72 - 60) = 178 pounds

The IBW for a small-framed person AMAB is 10 percent less than 178, or 160 pounds, and the IBW for a large-framed person AMAB is 10 percent greater than 178, or 196 pounds.

So, for healthy people AMAB who are 6 feet tall, the IBW range is 160 to 196 pounds, depending on body frame size.

While your IBW may give you a specific number you can shoot for when you step on the scale, it may not be the best way to determine good health when it comes to your weight. Body mass index (BMI), on the other hand, estimates body composition and ‌may‌ be better determining health risks than IBW, according to another May 2016 article in ‌The American Journal of Clinical Nutrition‌.

Like ideal body weight, a mathematical formula is used to estimate BMI; all you need is your height and weight, per the Centers for Disease Control and Prevention. Keep in mind, however, that BMI is not the end-all, be-all for determining your health status. There are many other ways to determine a healthy 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 -foot-tall person AMAB who weighs 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 people AMAB of this height.

Formulas that calculate IBW and BMI can help you get a good idea of where the scale should be ‌around‌, but they're definitely not perfect. And while BMI offers a fair estimate of body fat for most people (while IBW does not — it's a linear formula), it has its limitations, according to the Mayo Clinic. BMI underestimates body fat for older people or people with low muscle mass and overestimates body fat for those who are very muscular.

"A BMI chart is not the best for those who are building muscle and lifting weight," says Jim White, RDN, CPT, certified personal trainer and owner of Jim White Fitness & Nutrition Studios in Virginia. He notes that he's seen bodybuilders with 6 percent body fat who are considered to have obesity based on their BMI. "That's because it takes into account our average height and weight, but doesn't dissect the kind of weight we have."

The best way to figure out someone's "ideal weight," he says, is to focus on measurements like waist-to-hip ratio or body fat percentage.

"These two can be great ways to assess increased risk for diseases while being more realistic than weighing in. Weight is influenced by so many things, such as muscle mass, water, salt, food, etc.," he says.

Lastly, if you need a little guidance, talk to a certified trainer or registered dietitian, and get help setting a realistic goal weight for your body type.