Waist-to-Height Ratio Calculator
The waist-to-height ratio (WHtR) is calculated by dividing waist circumference by height, using the same units for both measurements. Because the ratio is dimensionless, it gives the same result in centimetres or in inches. WHtR is gaining recognition as a practical screening tool for cardiometabolic risk because abdominal fat (captured by waist circumference) is more closely linked to insulin resistance, cardiovascular disease, and metabolic syndrome than overall body mass. The key guideline, widely publicised by Margaret Ashwell, is to keep your waist less than half your height: a WHtR below 0.5 corresponds to lower health risk. This calculator uses a five-band risk table: very low risk (below 0.40), low risk (0.40 to 0.49), increased risk (0.50 to 0.59), high risk (0.60 to 0.62), and very high risk (0.63 and above). To measure waist circumference accurately, stand upright, breathe out gently, and measure at navel height with a snug but non-compressing tape. Height should be measured without shoes. Enter both measurements in the same unit (cm or inches) to calculate your WHtR.
Your WHtR is --, which indicates --.
How WHtR is calculated
The calculation is straightforward: divide waist circumference by height, both measured in the same unit. The result is dimensionless and does not change between centimetres and inches.
WHtR = waist circumference / height (same units)
Example: waist 80 cm, height 175 cm: WHtR = 80 / 175 = 0.4571
Worked example
Waist 80 cm, height 175 cm:
- WHtR = 80 / 175 = 0.4571
- 0.4571 is between 0.40 and 0.49, so the category is: Low risk
- The boundary waist (0.50 × 175 cm) = 87.5 cm
WHtR health risk categories
| WHtR range | Health risk category | Guidance |
|---|---|---|
| Below 0.40 | Very low risk | Waist is well under half the height; very lean abdomen |
| 0.40 to 0.49 | Low risk | Waist under half the height; associated with lower cardiometabolic risk |
| 0.50 to 0.59 | Increased risk | Waist at or above half the height; review diet and activity levels |
| 0.60 to 0.62 | High risk | Substantially elevated abdominal fat; consult a healthcare provider |
| 0.63 and above | Very high risk | Very high central adiposity; medical review recommended |
WHtR versus BMI: key differences
BMI (weight/height²) captures overall body mass relative to height but does not distinguish between abdominal fat and fat elsewhere, or between fat and muscle. WHtR captures the relationship between abdominal girth and height, which research associates more directly with cardiometabolic outcomes. Neither measure is diagnostic on its own, and both are best used as screening tools alongside clinical assessment.
Waist-to-height ratio: frequently asked questions
What is the waist-to-height ratio?
The waist-to-height ratio (WHtR) is a simple dimensionless measure calculated by dividing waist circumference by height, using the same unit for both. Because it is dimensionless, the result is the same whether you use centimetres or inches. Research by Margaret Ashwell and colleagues, published in peer-reviewed literature including BMJ Open, has shown WHtR to be a useful predictor of cardiometabolic risk, sometimes outperforming BMI because it directly captures central (abdominal) adiposity.
What is a healthy waist-to-height ratio?
The widely cited boundary value is 0.5. Ashwell and others have summarised this as: keep your waist to less than half your height. A WHtR below 0.5 is generally associated with lower cardiometabolic risk in adults. Values of 0.5 and above are associated with progressively higher risk. Very high values (0.63 and above) are associated with markedly elevated risk.
How do I measure my waist circumference correctly?
Stand upright and breathe out normally. Place a tape measure around your bare abdomen at the level of the navel (or at the midpoint between the lower rib and the top of the hip bone). The tape should be snug but not compressing the skin. Take the measurement at the end of a gentle breath out. The WHO recommends measuring at the midpoint between the lowest rib and the iliac crest.
Does WHtR vary by sex or ethnicity?
Some researchers propose slightly different thresholds by sex, with women typically having a higher optimal WHtR than men at the same risk level. Ethnicity-specific thresholds have also been proposed, particularly for South Asian and East Asian populations where lower absolute waist values are associated with higher risk. The universal 0.5 threshold is a practical, population-level screening guideline rather than a precise clinical cut point.
Is WHtR better than BMI?
WHtR and BMI measure different things. BMI is a simple weight-for-height index; WHtR captures central adiposity, which is more directly linked to insulin resistance, cardiovascular risk, and metabolic syndrome. Several meta-analyses have found WHtR slightly outperforms BMI for predicting cardiometabolic outcomes, but both are screening tools rather than diagnostic tests. A healthcare provider will use multiple measures together.
Official sources
- WHO waist circumference reference: WHO Waist Circumference and Waist-Hip Ratio: Report of a WHO Expert Consultation.
- Ashwell M, Gunn P, Gibson S. Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors: systematic review and meta-analysis. Obes Rev. 2012;13(3):275-286. See also: PubMed Central.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology. General information only, not medical advice.