THE NUMORIX GUIDE
How to use the Body Type Calculator
Last reviewed September 14, 2026
What this calculator does
The engine calculates waist-to-hip ratio as waist / hips and shoulder-to-hip ratio as shoulders / hips.
Formula and method
The engine calculates waist-to-hip ratio as waist / hips and shoulder-to-hip ratio as shoulders / hips. It then checks ordered rules: inverted triangle if shoulders/hips > 1.1 and waist/hips < 0.8; rectangle if shoulders/hips > 1.05 and waist/hips is 0.70-0.85; hourglass if shoulders/hips < 1.0 and waist/hips < 0.75; triangle if waist/hips > 0.85 and shoulders/hips < 1.05; apple if waist/hips > 0.9 or shoulders/hips > 1.1; otherwise athletic.
Variables and inputs
Shoulders, waist, and hips are entered in inches. Only the relative ratios matter, so another length unit works only if all three measurements use that same unit. The UI rejects nonpositive values and displays both ratios to two decimals.
Worked example
For 44 in shoulders, 32 in waist, and 38 in hips: waist-to-hip = 32 / 38 = 0.84 and shoulder-to-hip = 44 / 38 = 1.16. The rectangle rule is the first matching rule, so the engine returns Rectangle.
How to interpret the result
The label is a descriptive proportion category generated by the route's thresholds. It does not measure health, attractiveness, athletic ability, or disease risk, and a person near a boundary may switch labels with a small measurement difference.
Common mistakes to avoid
Measure the same anatomical landmarks each time, use the same unit for every circumference, and keep the ratio direction as waist divided by hips and shoulders divided by hips. Do not treat clothing size as a substitute for tape measurements.
Assumptions and limitations
The categories and cutoffs are hardcoded and not a validated medical classification. Several rules overlap, so their order changes the outcome; the engine does not model sex, age, muscle distribution, posture, or measurement uncertainty. A body-type label should not guide medical or nutrition decisions.