Two people with the same height can have very different ideal weights — not because of diet or fitness level, but because of the size of their skeleton. A person with a large frame has more bone mass and naturally weighs more at the same level of health. Knowing your frame size helps you set a weight target that's realistic for your actual build — not one sized for someone with a completely different skeleton.
The approximate adjustment applied to ideal body weight calculations for frame size. Large-framed individuals add ~10%; small-framed individuals subtract ~10% from a medium-frame baseline.
How to Determine Your Frame Size
The most practical way to estimate frame size is with wrist circumference measured with a tape measure. Wrap the tape measure around your wrist at the smallest point, just above the wrist bone.
Women's Frame Size by Wrist Circumference
| Height | Small Frame | Medium Frame | Large Frame |
|---|---|---|---|
| Under 5'2" | Less than 5.5" | 5.5" – 5.75" | More than 5.75" |
| 5'2" – 5'5" | Less than 6" | 6" – 6.25" | More than 6.25" |
| Over 5'5" | Less than 6.25" | 6.25" – 6.5" | More than 6.5" |
Men's Frame Size by Wrist Circumference
| Height | Small Frame | Medium Frame | Large Frame |
|---|---|---|---|
| Under 5'5" | Less than 5.5" | 5.5" – 6.5" | More than 6.5" |
| 5'5" – 5'9" | Less than 6" | 6" – 7" | More than 7" |
| Over 5'9" | Less than 6.5" | 6.5" – 7.5" | More than 7.5" |
The Hamwi Formula: Ideal Weight by Height and Frame
The Hamwi method, developed in 1964 and still used in clinical nutrition, provides a straightforward formula for ideal body weight:
For women: 100 lbs for the first 5 feet, plus 5 lbs for each additional inch
For men: 106 lbs for the first 5 feet, plus 6 lbs for each additional inch
Then apply frame size adjustments: add 10% for large frame, subtract 10% for small frame.
Example: 5'6" Medium-Frame Woman
- Base: 100 lbs (first 5 feet)
- Additional inches: 6 × 5 = 30 lbs
- Medium-frame baseline: 130 lbs
- Small frame adjustment: 130 − 13 = 117 lbs
- Large frame adjustment: 130 + 13 = 143 lbs
Hamwi Ideal Weight Reference Table — Women
| Height | Small Frame | Medium Frame | Large Frame |
|---|---|---|---|
| 5'0" | 90 lbs | 100 lbs | 110 lbs |
| 5'2" | 99 lbs | 110 lbs | 121 lbs |
| 5'4" | 108 lbs | 120 lbs | 132 lbs |
| 5'6" | 117 lbs | 130 lbs | 143 lbs |
| 5'8" | 126 lbs | 140 lbs | 154 lbs |
| 5'10" | 135 lbs | 150 lbs | 165 lbs |
| 6'0" | 144 lbs | 160 lbs | 176 lbs |
Hamwi Ideal Weight Reference Table — Men
| Height | Small Frame | Medium Frame | Large Frame |
|---|---|---|---|
| 5'4" | 115 lbs | 130 lbs | 143 lbs |
| 5'6" | 128 lbs | 142 lbs | 156 lbs |
| 5'8" | 140 lbs | 154 lbs | 169 lbs |
| 5'10" | 152 lbs | 166 lbs | 183 lbs |
| 6'0" | 164 lbs | 178 lbs | 196 lbs |
| 6'2" | 175 lbs | 190 lbs | 209 lbs |
| 6'4" | 187 lbs | 202 lbs | 222 lbs |
Hamwi vs BMI: Which Is More Useful?
The Hamwi formula and BMI generally agree — the Hamwi medium-frame ideal weight typically falls around BMI 21–23, which is solidly in the WHO healthy range. The key advantage of the Hamwi approach is that it accounts for frame size variation, giving large-framed people a higher target and small-framed people a lower one — rather than treating everyone of the same height identically.
The WHO BMI healthy range (18.5–24.9) already accommodates this variation implicitly — it's a 37+ pound range for most heights. You can think of the lower third of the range as appropriate for small frames, the middle for medium frames, and the upper third for large frames.
For a precise, personalized BMI calculation, use the free CheckBMI calculator alongside the frame size guidance above.