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Body Frame Size

The wrist carries almost no fat, which makes it a clean place to measure frame. A larger height-to-wrist figure means a finer frame.

Your numbers

Frame index

10

Wrist (cm)

17cm

Height (cm)

170cm

What it means

10 is a medium frame.

Formula

Frame index = Height (cm) ÷ Wrist (cm)

Frame size only nudges a reference weight by a few kilograms; it is not a health measure. A big frame says nothing about body fat.

What to enter

InputDefaultAccepted range
Height (cm) (cm)Height in centimetres; converted to metres inside the formula.17050 and up
Wrist (cm) (cm)The narrowest point of the wrist; almost no fat, so it reflects frame.178 ~ 30

Step by step

FormulaFrame index = Height (cm) ÷ Wrist (cm)
With the default numbersFrame index = 170 ÷ 17
AnswerFrame index = 10

Quick reference table

Results when only Height (cm) (cm) changes and everything else stays put.

Height (cm) (cm)Frame indexWrist (cm) (cm)Height (cm) (cm)
8551785
1287.5317128
1701017170
2551517255
3402017340

What each result means

ResultAt default values
Frame indexHeight over wrist circumference; larger means a finer frame.10
Wrist (cm) (cm)The narrowest point of the wrist; almost no fat, so it reflects frame.17
Height (cm) (cm)Height in centimetres; converted to metres inside the formula.170

Common mistakes

Frame size only nudges a reference weight by a few kilograms; it is not a health measure. A big frame says nothing about body fat.

Glossary

Height (cm)
Height in centimetres; converted to metres inside the formula.
Wrist (cm)
The narrowest point of the wrist; almost no fat, so it reflects frame.
Frame index
Height over wrist circumference; larger means a finer frame.

Frequently asked questions

Q. How is Body Frame Size calculated?

Frame index = Height (cm) ÷ Wrist (cm) — The wrist carries almost no fat, which makes it a clean place to measure frame. A larger height-to-wrist figure means a finer frame.

Q. Can you walk through an example?

With Height (cm) 170cm, Wrist (cm) 17cm, the answer is Frame index 10.

Q. What do I need to enter?

Enter Height (cm), Wrist (cm). The result recalculates as you type, and an empty box counts as zero.

Q. How much does the answer move if I change a number?

Changing only Height (cm) (cm) moves the answer to Height (cm) (cm) 85 → Frame index 5 and Height (cm) (cm) 340 → Frame index 20. The table below lays out five steps.

Q. How are the numbers rounded?

Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.

Q. Anything to watch out for?

Frame size only nudges a reference weight by a few kilograms; it is not a health measure. A big frame says nothing about body fat.

Related calculators

These calculators help you understand health figures; they do not replace diagnosis or prescription. See a clinician if you have symptoms.