Waist-to-height ratio
Compute your waist-to-height ratio (WHtR) and see your risk level.
- Instant
- Free
- Private (processed locally)
- No sign-up
The half rule, in one calculation
The waist-to-height ratio simply divides your waist by your height. Under 0.5 you are in the healthy zone; above it, risk increases. The tool shows the ratio and your category.
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Measure the waist
Around the navel, without tightening.
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Enter the height
Same unit (cm or inches).
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Read the ratio
And your risk level.
Categories (Ashwell)
| Ratio | Category | Example |
|---|---|---|
| < 0.4 | Underweight — take care | — |
| 0.4 – 0.5 | Healthy | 80 / 170 = 0.47 |
| 0.5 – 0.6 | Increased risk | 90 / 170 = 0.53 |
| ≥ 0.6 | High risk | — |
A general health indicator, not a diagnosis. For personal advice, consult a professional. 100% local calculation.
Frequently asked questions
What is the waist-to-height ratio?
It is the waist circumference divided by height (same units). WHtR estimates abdominal fat, linked to cardiometabolic risk. Simple rule: “keep your waist under half your height”.
What are the thresholds?
Per Ashwell’s approach: under 0.4 (underweight, take care), 0.4 to 0.5 (healthy), 0.5 to 0.6 (increased risk), 0.6 and above (high risk). The 0.5 threshold is the main alert.
Is it better than BMI?
WHtR captures fat distribution (belly), which BMI ignores. It is often a better predictor of cardiovascular risk, especially for muscular or average-height people. The two are complementary.
How do I measure the waist correctly?
Measure midway between the lowest rib and the top of the hip (iliac crest), at the end of a normal exhale, without tightening the tape. Use the same unit as for height.