Sitting Height Ratio Calculator (Cormic Index)
Trunk-to-stature proportion — the anthropometric index behind bike fitting, cockpit design and growth assessment.
Most adults sit between 50 and 55% — proportion varies systematically between populations and is exactly why two people of identical height need different saddle heights and desk setups. Ergonomists and growth specialists use sitting height because limbs and trunk grow on different schedules.
Formula
For general information only — not medical advice, a diagnosis or a treatment plan. Consult a qualified healthcare professional before making health, diet, medication or exercise decisions.
Trunk-to-stature proportion — the anthropometric index behind bike fitting, cockpit design and growth assessment. The Sitting Height Ratio Calculator (Cormic Index) is a free, private sitting height ratio tool — every result computes instantly in your browser with no sign-up and no data upload.
About Sitting Height Ratio Calculator (Cormic Index)
Most adults sit between 50 and 55% — proportion varies systematically between populations and is exactly why two people of identical height need different saddle heights and desk setups. It applies Cormic index = sitting height ÷ standing height × 100. Use the Sitting Height Ratio Calculator (Cormic Index) to get an instant, clearly-explained result with the working shown step by step — free, private and with the source method cited.
How to use Sitting Height Ratio Calculator (Cormic Index)
- 1Enter your details in the Sitting Height Ratio Calculator (Cormic Index) input fields above.
- 2The result updates instantly with the working and reference bands shown.
- 3Adjust any value to explore how it changes the outcome — it's free and unlimited.
Why use Sitting Height Ratio Calculator (Cormic Index)?
- ✓Instant sitting height ratio result that recomputes as you type — no waiting, no page reloads
- ✓100% client-side: your health data never leaves your browser
- ✓Shows the actual formula and your numbers substituted in, so you can see exactly how the result is reached
- ✓Based on published, citable sources (Norgan NG, Ann Hum Biol 1994 — population differences in the Cormic index)
- ✓Free forever with no sign-up, account or app install
Frequently asked questions
How does the Sitting Height Ratio Calculator (Cormic Index) work?+
Most adults sit between 50 and 55% — proportion varies systematically between populations and is exactly why two people of identical height need different saddle heights and desk setups. The calculation uses the formula: Cormic index = sitting height ÷ standing height × 100. Everything runs instantly in your browser as you type — your inputs are never uploaded.
Is the Sitting Height Ratio Calculator (Cormic Index) accurate, and what is it based on?+
The method is traceable to authoritative sources: Norgan NG, Ann Hum Biol 1994 — population differences in the Cormic index. Results are estimates — individual variation always applies, so treat the output as a well-grounded starting point.
Is the Sitting Height Ratio Calculator (Cormic Index) free and private?+
Yes. It's completely free with no sign-up, and all computation happens locally in your browser, so none of your health data ever leaves your device.
Can I use this for medical decisions?+
This tool is for general information only and is not medical advice. Always consult a qualified healthcare professional before making health decisions.
What can I use the Sitting Height Ratio Calculator (Cormic Index) for?+
It's commonly used for sitting height ratio, cormic index, trunk leg proportion. Trunk-to-stature proportion — the anthropometric index behind bike fitting, cockpit design and growth assessment.
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