Waist-to-Height Ratio Calculator
Calculate your waist-to-height ratio (WHtR) and compare it with the published boundary values around 0.5.
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What this tool does
Calculate your waist-to-height ratio (WHtR) and compare it with the published boundary values around 0.5. Measure the waist at the midpoint between the lowest rib and the iliac crest, at the end of a normal breath. Boundary values are population screening guides, not diagnosis.
How to use the Waist-to-Height Ratio Calculator
- Enter or select waist circumference in in.
- Enter or select height in in.
- Read the calculated result; change any measurement to compare alternatives.
Formula
WHtR = waist / height (same units); published boundary values: below 0.4 low, 0.4–0.49 healthy range, 0.5–0.59 increased, 0.6+ higher (Ashwell boundary-value literature)
- waist
- Waist circumference (in, before metric conversion)
- height
- Height (in, before metric conversion)
Measure the waist at the midpoint between the lowest rib and the iliac crest, at the end of a normal breath. Boundary values are population screening guides, not diagnosis.
Worked example
For waist-to-height ratio calculator, the following measurements illustrate the exact method: Waist circumference: 34; Height: 69.
Inputs
- Waist circumference34 in
- Height69 in
Result
- Waist-to-height ratio0.49
- Published boundary band0.4–0.49 — healthy range
- Waist at the 0.5 boundary34.5 in
Results explained
- Waist-to-height ratio
- Waist-to-height ratio from the formula above. Measure the waist at the midpoint between the lowest rib and the iliac crest, at the end of a normal breath. Boundary values are population screening guides, not diagnosis.
- Published boundary band
- Published boundary band from the formula above. Measure the waist at the midpoint between the lowest rib and the iliac crest, at the end of a normal breath. Boundary values are population screening guides, not diagnosis.
- Waist at the 0.5 boundary
- Waist at the 0.5 boundary from the formula above, expressed in in before metric conversion. Measure the waist at the midpoint between the lowest rib and the iliac crest, at the end of a normal breath. Boundary values are population screening guides, not diagnosis.
Frequently asked questions
The widely used boundary value is 0.5 — 'keep your waist below half your height'. Published bands put 0.4–0.49 in the healthy range, 0.5–0.59 as increased, and 0.6+ as higher.
At the midpoint between your lowest rib and the top of your hip bone (iliac crest), standing relaxed, at the end of a normal exhale — not over clothing and not pulled tight.
WHtR captures central fat distribution, which BMI misses, and research (Ashwell and colleagues) finds it a useful screening complement to BMI. Neither replaces individual assessment.
The 0.5 boundary value has been proposed across ages and both sexes as a simple message, but children's results should be interpreted with age-specific guidance from a clinician.
It places you in the published 'consider action' band: a screening flag, not a diagnosis. Lifestyle review and, if concerned, a clinician visit are the appropriate next steps.