What body frame size means
Body frame size (small, medium, or large) refers to the size of your skeletal structure. It is commonly estimated from the ratio of your height to your wrist circumference, since wrist size correlates reasonably well with overall bone structure.
How this calculator works
Enter your sex, height, and wrist circumference. The calculator divides your height by your wrist circumference (both in inches) and compares the result to standard reference thresholds: for men, a ratio above 10.4 indicates a small frame, 9.6 to 10.4 indicates medium, and below 9.6 indicates a large frame. For women, the thresholds are above 11.0 for small, 10.1 to 11.0 for medium, and below 10.1 for large.
Frame size is often used alongside healthy weight charts, since people with larger frames typically carry more lean mass at a healthy weight than people with smaller frames. This tool is for general educational and planning purposes only.