Body Frame Size Calculator
Determine whether you have a small, medium or large body frame from your height and wrist size — the missing piece when interpreting ideal-weight ranges.
Your Measurements
Measure around the wrist below the bone
Body Frame Size
Medium
Height ÷ wrist ratio: 10.0
Frame Size
Medium
Height/Wrist Ratio
10.00
Sex
Male
Wrist
17 cm
How It Works
Two people of the same height can have very different healthy weights because of their skeletal build — their frame size. This calculator estimates frame size using the ratio of your height to your wrist circumference, a bony measurement that reflects your skeletal structure. A higher ratio (a thinner wrist for your height) means a smaller frame; a lower ratio means a larger frame. Frame size matters because ideal-weight tables assume a medium build — a large-framed person can healthily weigh more, and a small-framed person less, than the table midpoint. Measure your wrist just below the wrist bone, on your dominant hand, with a tape. The calculator applies the standard sex-specific thresholds and returns Small, Medium or Large, which you can use alongside our ideal-weight calculator for a more personal target.
Formula
Frame is based on the ratio r = Height ÷ Wrist circumference. Men: small r>10.4, medium 9.6–10.4, large <9.6. Women: small r>11, medium 10.1–11, large <10.1.
Frequently Asked Questions
How is body frame size measured?
By the ratio of your height to your wrist circumference. Measure your wrist just below the wrist bone; a thinner wrist relative to height means a smaller frame, a thicker wrist a larger one.
Why does frame size matter for ideal weight?
Ideal-weight formulas assume a medium build. A large-framed person can healthily carry more weight and a small-framed person less, so knowing your frame refines the target range.
Where do I measure my wrist?
Around the wrist of your dominant hand, just below the wrist bone (the bump), where the wrist is narrowest. Keep the tape snug but not tight.
Is wrist size an accurate measure of frame?
It is a simple, reasonable proxy for skeletal build because the wrist has little fat or muscle. It is an estimate, not a precise medical measure, but it works well for interpreting weight ranges.
Can I change my frame size?
No — frame size reflects your bone structure, which is fixed in adulthood. You can change your weight and body composition, but not your underlying skeletal frame.