Waist to Height Ratio Calculator
Divide your waist by your height to get your waist-to-height ratio (WHtR), a simple measure of fat around the middle. See which health band you are in and the waist size that keeps you under the 0.5 rule: keep your waist to less than half your height.
Midway between the lowest rib and the top of the hip bone, after breathing out
Midway between the lowest rib and the top of the hip bone, after breathing out
How to use the Waist to Height Ratio Calculator
- Choose units: centimeters or feet and inches.
- Measure your waist midway between your lowest rib and the top of your hip bone, after breathing out normally.
- Enter your height.
- Read your ratio, its health band and your target waist size.
- Use the table to see waist cutoffs for other heights.
Waist to height ratio formula and bands
WHtR = waist circumference ÷ height, both in the same unit. Example: an 84 cm waist and a height of 175 cm give 84 ÷ 175 = 0.48.
| Ratio | Band | Meaning |
|---|---|---|
| Below 0.40 | Low | Uncommon in adults; may go with being underweight |
| 0.40–0.49 | Healthy | No increased risk from central fat |
| 0.50–0.59 | Increased risk | More fat around the middle than is healthy |
| 0.60 or more | High risk | Strongly linked with heart disease and type 2 diabetes |
Maximum waist for a ratio of 0.5
| Height | Waist under | Height | Waist under |
|---|---|---|---|
| 150 cm | 75 cm | 5 ft 0 in | 30 in |
| 160 cm | 80 cm | 5 ft 4 in | 32 in |
| 170 cm | 85 cm | 5 ft 8 in | 34 in |
| 180 cm | 90 cm | 6 ft 0 in | 36 in |
| 190 cm | 95 cm | 6 ft 4 in | 38 in |
The ratio is a screening measure, not a diagnosis. It is less reliable during pregnancy, and very muscular or very short or tall people should interpret it alongside other measures.
Frequently asked questions
What is a healthy waist to height ratio?
A ratio from 0.4 to 0.49 is generally considered healthy. From 0.5 to 0.59 indicates increased health risk, and 0.6 or more indicates high risk. These bands are used, for example, in the UK NICE guidance published in 2022.
What is the 0.5 rule?
Keep your waist circumference to less than half your height. For someone 170 cm tall that means a waist under 85 cm; for 5 ft 10 in (70 in), under 35 inches. It is a simple message that works across sexes and many ethnic groups.
How do I measure my waist for this?
Stand up, breathe out normally and place the tape horizontally midway between the bottom of your lowest rib and the top of your hip bone. Keep the tape snug but not tight. This is not always the same as your trouser size.
Why use waist to height ratio instead of BMI?
BMI does not show where fat is stored. Fat around the abdomen is more closely linked with heart disease and type 2 diabetes, and waist-to-height ratio captures that. Many experts suggest using both together.
Does it matter whether I use cm or inches?
No. The ratio has no units, so you get the same number in centimeters or inches as long as both measurements use the same unit. This calculator converts for you.
Does the ratio work for children?
A cutoff of 0.5 is also often used for children over about 5 years, but children's results should be interpreted by a health professional. NICE's adult guidance applies to people with a BMI under 35.