Body metrics · calculator
Waist-to-height ratio calculator
Belly fat around the organs drives blood pressure, blood sugar and cholesterol. The simple rule: keep your waist to less than half your height.
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What your ratio means
| Waist ÷ height | Meaning (NICE 2022) |
|---|---|
| 0.40–0.49 | Healthy — no increased risk |
| 0.50–0.59 | Increased health risk |
| 0.60 and above | High health risk |
A ratio below 0.4 is unusual in adults — re-check the measurement; it can also mean you are underweight. The 0.5 rule works for adults of all ethnic backgrounds and both sexes, which makes it simpler than waist-circumference cut-offs.
How to measure your waist
- Stand up straight and breathe out normally.
- Find the point midway between your lowest rib and the top of your hip bone — roughly at belly-button level.
- Wrap a tape measure around your bare waist, snug but not compressing the skin, parallel to the floor.
- Read the number at the end of a normal exhale. Measure twice and use the average.
Why belly fat matters
Fat stored around the organs (visceral fat) is metabolically active: it raises blood pressure, worsens insulin resistance and pushes up triglycerides. Studies show that waist-to-height ratio predicts heart disease and type 2 diabetes better than BMI. The good news: visceral fat is usually the first to go with regular activity and a lower-calorie diet. Related: BMI calculator · cholesterol calculator.
Screening tools give a first orientation, not a diagnosis. Talk to your doctor about your results, especially before major changes to diet, exercise or medication.