Waist-to-height ratio
A simple measure of central body fat that many researchers consider more informative than BMI on its own.
Measure your waist at the midpoint between your lowest rib and the top of your hip bone, breathing out normally.
The rule is easy to remember
Keep your waist to less than half your height. That single sentence is the whole guideline, and it works across populations without needing different thresholds for different ethnic groups — one of its real advantages over BMI.
How to measure properly
- Measure directly against skin, not over clothing.
- Find the midpoint between the bottom of your lowest rib and the top of your hip bone — roughly level with your navel for most people.
- Keep the tape snug but not compressing the skin.
- Breathe out normally and measure then. Do not hold it in.
Why waist matters more than total weight
Fat stored around the abdomen — around the organs rather than under the skin — is more strongly associated with type 2 diabetes, high blood pressure and heart disease than fat elsewhere. Two people can share a BMI while carrying very different amounts of this visceral fat, which is exactly the gap this measurement fills.
This is especially relevant for people of South Asian origin, who tend to carry proportionally more central fat at a given BMI. Using this alongside our BMI calculator gives a fuller picture than either alone.
Limits
It is not designed for children, and it is not valid during pregnancy. As with any single measurement, it is one input among many — blood pressure, blood sugar, lipids and family history all matter.