Waist-to-Height Ratio Calculator
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Waist-to-Height Ratio0.50
CategoryIncreased Risk
A simple guideline is to keep your waist less than half your height (ratio under 0.5). This is a screening estimate, not a medical diagnosis.
The Waist-to-Height Ratio Calculator divides your waist measurement by your height to screen for excess fat around the middle. Unlike BMI, this measure looks specifically at central or abdominal fat, which carries the strongest links to heart disease and type 2 diabetes. The well-known guideline is simple: keep your waist to less than half your height, meaning a ratio below 0.5.
Formula
WHtR = waist ÷ height
- waist
- Waist circumference at the navel
- height
- Standing height in the same unit as the waist
How it works
- Enter your waist circumference and your height using the same unit of measurement (both inches or both centimetres).
- The calculator divides waist by height to give a single ratio between roughly 0.3 and 0.8.
- It then maps the ratio onto thresholds: under 0.4 underweight, 0.4 to 0.5 healthy, 0.5 to 0.6 increased risk, and 0.6 or above high risk.
Worked example
A person with a 34-inch waist who is 68 inches (5 ft 8 in) tall.
- WHtR = 34 ÷ 68 = 0.50.
- The healthy band runs up to but not including 0.50.
- A ratio of exactly 0.50 falls at the start of the increased-risk band.
WHtR of 0.50, the boundary into the increased-risk band.
Frequently asked questions
- Does the unit of measurement matter?
- No, as long as both numbers use the same unit. Because the ratio divides one length by another, inches over inches and centimetres over centimetres give the identical result.
- Why use waist-to-height instead of BMI?
- Waist-to-height ratio captures where fat is stored rather than total weight. Abdominal fat is more metabolically harmful, so this ratio often flags risk that BMI alone misses, including in people of normal weight.
- Is the 0.5 cutoff the same for everyone?
- The 0.5 boundary works as a broad guideline across adults of different heights and both sexes, which is part of its appeal. Children and some athletic builds may need different interpretation, so use it as a screening tool.