Determine your body frame size — small, medium, or large — using your wrist circumference relative to height. Body frame size reflects bone density and skeletal size, which naturally affects ideal weight and should be used to interpret BMI and weight goals more accurately.
Your Frame Size
Frame Size—
Height/Wrist Ratio—
Ideal Weight Range—
Weight Status—
Frame Size Norms by Height and Wrist
Frame
Height/Wrist Ratio (Men)
Height/Wrist Ratio (Women)
Ideal Weight by Frame (Devine + Frame Adjustment)
Frame Size
Ideal Weight Range
Adjustment from Medium
Alternative Frame Size Methods
Method
How to Measure
Small
Medium
Large
Wrist/Height ratio
Wrap tape around dominant wrist
—
—
—
Thumb-finger encirclement
Wrap thumb and middle finger around opposite wrist
Overlap
Fingers touch
Gap between fingers
Elbow breadth (men)
Measure bony elbow points at 90°
< 2.5"
2.5–2.9"
≥ 3.0"
Elbow breadth (women)
Same method
< 2.1"
2.1–2.5"
≥ 2.6"
Understanding Body Frame Size
Body frame size refers to the overall size and density of the skeleton. People with larger frames have heavier bones relative to their height, which means they will naturally weigh more even at the same level of body fat as a smaller-framed person.
Standard weight tables and BMI interpretation assume a "medium" frame. Adjusting for frame size provides a more accurate personal weight goal:
Small frame: subtract ~10% from medium-frame ideal weight range
Medium frame: use standard ideal weight tables as-is
Large frame: add ~10% to medium-frame ideal weight range
Measuring Wrist Circumference
Use a flexible tape measure. Measure the circumference of your dominant wrist at the narrowest point (just below the wrist bones). The frame size formula divides height in centimeters by wrist circumference in centimeters.
Frequently Asked Questions
Frame size (small, medium, or large) refers to your bone structure — wrist circumference and elbow breadth are common measurements. Frame size affects ideal weight ranges because bone and connective tissue contribute to total body weight. A large-framed person can weigh 10–15 lbs more than a small-framed person of the same height while still being at a healthy body composition.
Wrist method: measure your wrist circumference. For women: small = under 5.5 in, medium = 5.5–5.75 in, large = over 5.75 in. For men: small = under 6.5 in, medium = 6.5–7.5 in, large = over 7.5 in (heights 5'5" and over). Elbow method: bend elbow 90°, feel for the two bony prominences, measure the gap — compare to height-specific reference tables.
BMI does not account for frame size, which is one of its limitations. A large-framed individual may have a BMI classified as "overweight" at a healthy body composition, while a small-framed person may appear "healthy" on BMI while carrying excess fat. Frame size is most useful when combined with BMI and body fat percentage for a complete picture.
A 5'10" (177.8 cm) male measures his wrist circumference at 6.3 inches (16 cm). Height-to-wrist ratio = 177.8 ÷ 16 = 11.1, which is above 10.4, classifying him as small frame. Using the Devine formula, medium-frame ideal weight at 5'10" is approximately 72.3 kg (159 lbs). Adjusted for small frame (−10%): 65–69 kg (143–152 lbs). If he currently weighs 165 lbs with a healthy body fat percentage, his BMI may show "normal" while his frame-adjusted ideal weight is slightly lower — illustrating why context matters.
Skeletal frame size is determined by genetics and is largely fixed after growth plates close in late adolescence. Bone density can change (especially with aging or conditions like osteoporosis), but bone dimensions and frame classification remain stable throughout adult life. This means your frame size measured at age 25 will still apply at age 65. Weight loss or gain may affect wrist circumference slightly due to fat padding, so for most accurate frame assessment, measure wrist at the wrist bones rather than including soft tissue.