How to use this calculator
- Enter or choose measured in.
- Enter or choose waist circumference.
- Enter or choose height.
- The waist-to-height ratio updates as you type. Use Copy result or Share to keep it.
Method
Waist-to-height ratio = Waist circumference ÷ Height (same units)
- Waist circumference
- measured midway between lowest rib and top of the hip bone
- Height
- standing height in the same unit
Worked example
- Ratio = 85 ÷ 170 = 0.50.
- NICE: 0.5 to 0.59 is increased central adiposity.
An 85 cm waist at 170 cm tall is a ratio of 0.50, which NICE classes as increased central adiposity.
What the result means
NICE categories: 0.4 to 0.49 healthy central adiposity; 0.5 to 0.59 increased central adiposity and increased health risk; 0.6 or more high central adiposity and further increased health risk. A rising ratio is a reason to talk to a GP or practice nurse, not a diagnosis.
Assumptions and limits
- NICE NG246 applies these categories to adults with a BMI under 35 and to children and young people, of both sexes and all ethnicities.
- The ratio is rounded to two decimals before it is categorised.
- It does not measure body fat directly and is less useful during pregnancy.
- Measurement technique matters: a tape placed at the navel or pulled tight changes the result.
Questions
Why use waist-to-height ratio as well as BMI?
BMI does not show where fat is stored. Fat around the abdomen is linked to type 2 diabetes and heart disease, and waist-to-height ratio picks this up.
Does it work in inches?
Yes. Because it is a ratio, any unit works as long as waist and height use the same one.
Sources
Please note: This is a general screening estimate for adults, not medical advice or a diagnosis. Talk to a qualified health professional about your health.