Waist to Height Ratio Calculator
The 'waist under half your height' rule — a quick central-fat risk check.
The Waist to Height Ratio Calculator applies one of the simplest and most robust health rules of thumb: keep your waist circumference under half your height. It divides waist by height and reports whether the result is below the 0.5 threshold linked to lower cardiometabolic risk.
Research has repeatedly shown that waist-to-height ratio predicts cardiovascular and metabolic risk at least as well as BMI — often better — because it captures where fat is stored. Belly (visceral) fat is metabolically active in ways subcutaneous fat is not, and this single ratio tracks it simply.
The tool also shows the maximum healthy waist for your height (exactly half your height), turning the guideline into an actionable number. It runs entirely in your browser — no account, no upload.
Waist-to-height ratio
0.45
Below 0.5 — within the healthy guideline
Max healthy waist
89.0 cm
= half your height
The waist-to-height ratio (under 0.5 recommended) captures central fatness better than BMI alone — 'keep your waist under half your height' is the memorable version.
How to use the Waist to Height Ratio Calculator
- Measure your waist at the navel with a relaxed stomach.
- Enter your waist in centimeters.
- Enter your height in centimeters.
- Read your ratio and whether it is below the 0.5 guideline.
- Check the maximum healthy waist for your height.
Frequently asked questions
Why is waist-to-height better than BMI for risk?
BMI cannot see where fat sits; waist-to-height captures central obesity, which drives metabolic risk. Studies find the 0.5 cutoff identifies cardiometabolic risk at least as accurately as BMI across age, sex and ethnicity.
How do I measure my waist correctly?
Stand relaxed, wrap the tape at navel level, keep it level and snug (not tight), and measure at the end of a normal exhale. Morning measurements before eating are most consistent for tracking.
Is 0.5 the rule for everyone?
The 'waist less than half height' guideline applies broadly to adults; research suggests slightly lower targets may be optimal in some Asian populations. It is a screening rule, not a diagnosis.
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