Waist-to-Height Ratio Calculator - Health Risk Check & Target Waist
Waist-to-Height Ratio Calculator
Keep your waist below half your height
One Simple Number
Divide your waist by your height. The rule of thumb is to keep the result below 0.5, whatever your age or sex.
Clear Risk Bands
See whether you fall below 0.4, in the healthy 0.4 to 0.49 range, or in the increased or high-risk bands.
Your Target Waist
Get the waist measurement that gives a 0.5 ratio and how far you are from it.
Full Privacy
Everything is calculated in your browser.
Why Waist-to-Height Ratio?
Fat carried around the middle is linked to a higher risk of heart disease and type 2 diabetes than fat elsewhere, and BMI cannot tell the two apart. The waist-to-height ratio adjusts for body size, so one guideline works across heights. In the UK, NICE guidance uses these bands: below 0.4 take care, 0.4 to 0.49 healthy, 0.5 to 0.59 increased risk, and 0.6 or more high risk.
This is a screening indicator, not a diagnosis. It can mislead for very muscular people, children, older adults and some ethnic groups, and it does not replace blood pressure, blood tests or a medical check-up. Measure your waist at the same point each time, relaxed and breathing out, and speak to a doctor about your own health.
Key Takeaways
- Both unit systems: Switch to inches and your entries convert automatically.
- Visual scale: A marker shows where your ratio sits between 0.3 and 0.7.
- Information only: Not a diagnosis or medical advice.