Waist-to-Height Ratio Calculator
Your waist-to-height ratio, where it sits against the 0.5 cut-off and the NICE bands, and the waist that would give 0.5.
Result…
How it's calculated
Waist-to-height ratio = waist ÷ height (same units) NICE NG246: 0.4 to 0.49 healthy · 0.5 to 0.59 increased · 0.6 or more high central adiposity Waist for a ratio of 0.5 = height × 0.5
The ratio is your waist divided by your height, both in the same units, so it has no units and works the same in centimetres or inches (1 in = 2.54 cm exactly). The simple message is to keep your waist to less than half your height. NICE's guideline on overweight and obesity (NG246, which carries forward its 2022 update) classifies central adiposity as healthy from 0.4 to 0.49, increased from 0.5 to 0.59 and high at 0.6 or more, for adults with a BMI under 35 kg/m², and advises using it alongside BMI. NICE gives no band below 0.4. Measure midway between the bottom of the ribs and the top of the hips, just above the belly button, after breathing out. For fat distribution by hips instead, use the waist-to-hip ratio.
Your numbers, step by step
About the Waist-to-Height Ratio calculator
This waist-to-height ratio calculator divides your waist by your height and shows where the result sits against the 0.5 cut-off, the point where your waist is half your height. It also places the ratio in the bands NICE, the health guidance body for England, uses for adults: 0.4 to 0.49 healthy, 0.5 to 0.59 increased and 0.6 or more high central adiposity, meaning fat around the middle. Because the ratio has no units, it works the same in centimetres or in feet and inches. The calculator also gives the waist that would give a ratio of 0.5 or 0.6 for your height, and how far your waist is from half your height. Waist size adds something BMI misses, since fat carried around the middle is linked with type 2 diabetes and heart disease. The steps show the division with your measurements.
How to use it
- Choose “Units”: metric for centimetres, imperial for inches and feet.
- Measure your “Waist” midway between the bottom of your ribs and the top of your hips, after breathing out naturally.
- Enter your “Height”.
- Read your ratio, its NICE band and the waist that would give a ratio of 0.5.
Worked example
A waist of 88 cm and a height of 168 cm give 88 ÷ 168 = 0.52. That is at or over the 0.5 cut-off and in NICE's increased central adiposity band (0.5 to 0.59). Half the height is 84 cm, so the waist is 4 cm over it; a ratio of 0.6 would be a waist of 100.8 cm.
Updated
Questions people ask
How do I calculate my waist-to-height ratio?
Measure your waist and your height in the same units and divide the waist by the height. NICE's own example is 96.5 cm ÷ 170 cm, or 38 in ÷ 67 in, both 0.57.
What is a healthy waist-to-height ratio?
NICE's guideline NG246 classes 0.4 to 0.49 as healthy central adiposity, 0.5 to 0.59 as increased and 0.6 or more as high, for adults with a BMI under 35 of both sexes and all ethnicities. In plain terms, keep your waist to less than half your height.
Where exactly should I measure my waist?
Find the bottom of your ribs and the top of your hips, and wrap the tape midway between them, just above the belly button. Breathe out naturally before reading it, and don't measure over thick clothes.
Is waist-to-height ratio better than BMI?
It measures something different: where fat is carried rather than total weight for height. NICE advises using it alongside BMI, not instead of it. You can check yours with the BMI calculator.
What are the limits of this ratio?
The NICE bands are for adults with a BMI under 35; they don't apply in pregnancy, and children are assessed differently. A ratio is a screening measure, not a diagnosis, so ask a doctor or nurse if you're concerned. For fat distribution by hips, try the waist-to-hip ratio calculator.