Waist-to-height ratio calculator
Enter your waist and height, get your ratio.
How do I calculate waist-to-height ratio?
Divide your waist by your height, both in the same unit. The NICE example: a 38-inch waist and 67-inch height give 0.57.
What is a healthy waist-to-height ratio?
NICE (the UK’s National Institute for Health and Care Excellence) classes 0.4 to 0.49 as healthy, 0.5 to 0.59 as increased health risk and 0.6 or more as further increased risk. The simple goal: keep your waist to less than half your height.
How do I measure my waist for this?
Midway between the bottom of the ribs and the top of the hips, after breathing out naturally.
Who does it apply to?
NICE uses these bands for adults with a BMI under 35 of both sexes and all ethnicities, including people with high muscle mass, and for children and young people aged 5 and over.
Why use it along with BMI?
BMI does not show where fat is carried. Fat around the waist is linked to higher health risks, which the waist-to-height ratio picks up.
Worked example: the same method in inches and in centimeters
With a 38-inch waist and a height of 67 inches, the ratio is 38 ÷ 67 = 0.57, in the 0.5 to 0.59 band (increased). Half the height is 33.5 inches, so a waist near 33.5 inches or less would put the ratio at 0.5 or lower. In centimeters the same logic holds: a person 175 cm tall with an 85 cm waist has a ratio of 0.49 (healthy band), while a 96 cm waist gives 0.55 (increased). The ratio has no unit, so the answer is the same in any system as long as the waist and height use the same one.
Why is the waist-to-height ratio used instead of waist alone?
Dividing the waist by height lets one set of cutoffs apply to people of different heights, which a single waist cutoff does not. A 2012 systematic review and meta-analysis in Obesity Reviews (Ashwell, Gunn and Gibson) pooled 31 studies covering more than 300,000 adults and found that waist-to-height ratio discriminated cardiometabolic risk factors such as diabetes and hypertension better than waist circumference or BMI in both men and women, and the authors proposed it as a screening tool. Screening only flags who may benefit from a closer look; it is not a diagnosis.
Common mistakes with the waist-to-height ratio
Mixing units: a 96 cm waist divided by a height of 69 inches gives 1.39, which is meaningless; convert one of them first, or use the unit selector. Measuring over thick clothing or at the belt line instead of midway between the ribs and the hips. Measuring with the stomach pulled in or after a deep breath. Applying the bands to a child under 5, which NICE does not cover. And reading a ratio below 0.4 as a target: NICE does not classify that range, so the calculator reports it without a band.
Sources and related calculators
Sources: NICE, “Overweight and obesity management” (NG246, 2025), recommendations on waist-to-height ratio; M. Ashwell, P. Gunn and S. Gibson, “Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors: systematic review and meta-analysis,” Obesity Reviews (2012). Related: BMI calculator, waist-to-hip ratio calculator, body fat calculator and Army body fat calculator.
For general information only — not medical advice. Talk with your doctor or another health professional about your own health. How we check our calculators.