Frame Size Index Calculator

How it is calculated

The index is a simple ratio: frame index = height ÷ wrist circumference, with both measured in centimetres. A bigger wrist relative to height gives a lower index. The category depends on sex. For men, an index above 10.4 is a small frame, 9.6 to 10.4 is medium and below 9.6 is large. For women, above 11 is small, 10.1 to 11 is medium and below 10.1 is large. The tool also reports the wrist as a percentage of height, wrist ÷ height × 100. Height must be 50 to 272 cm and the wrist 5 to 40 cm, otherwise no result appears; any sex value other than female is treated as male. The cut-offs are fixed and apply to adults; they say nothing about children, and other reference tables use different boundaries.

Common mistakes

• Entering height or wrist in inches. A wrist of 6.5 is accepted as centimetres, and with a height of 69 it gives a meaningless Small frame, so convert both to centimetres first.
• Measuring the wrist loosely or over the bony bumps instead of just above the wrist bone. A 1 cm error moves the index by about 0.6, enough to change the category.
• Ignoring the sex setting. An index of 10.00 is a medium frame for a man but a large frame for a woman, because the cut-offs differ; leaving it on the default uses the male cut-offs.
• Reading a higher index as a bigger frame. It is the opposite, because the wrist sits in the denominator.