How to use it
- Choose your sex.
- Measure and enter your waist and hips.
- Enter your height for the waist-to-height ratio.
- Read the three results and their risk levels.
Why waist size matters
Fat stored around the abdomen (visceral fat) is more strongly linked to type 2 diabetes, high blood pressure and heart disease than fat on the hips and thighs. BMI doesn't show where fat is, so waist measurements add useful information, especially if your BMI is in the normal or overweight range.
The three measures and their cutoffs
| Measure | Men | Women | Risk |
|---|---|---|---|
| Waist circumference | over 37 in (94 cm) | over 31.5 in (80 cm) | increased |
| Waist circumference | over 40 in (102 cm) | over 35 in (88 cm) | substantially increased |
| Waist-to-hip ratio | 0.90 or more | 0.85 or more | substantially increased |
| Waist-to-height ratio | 0.50–0.59 / 0.60+ | 0.50–0.59 / 0.60+ | increased / high |
The waist and waist-to-hip cutoffs are from the World Health Organization; the 40-inch and 35-inch waist thresholds are also the ones used by the CDC and NIH. The waist-to-height categories come from the UK's NICE guideline, which recommends keeping your waist to less than half your height.
Worked example
A woman who is 5 ft 6 in (66 in) tall, with a 31-inch waist and 39.5-inch hips:
- Waist-to-hip ratio: 31 ÷ 39.5 = 0.78, below the WHO cutoff of 0.85.
- Waist: 31 in, under 31.5 in, so not increased.
- Waist-to-height ratio: 31 ÷ 66 = 0.47, in the healthy 0.40–0.49 range. Her waist goal would be under 33 in.
How to measure
Stand up straight and breathe out normally. Use a flexible, non-stretch tape held level all the way around, snug but not squeezing the skin.
- Waist: halfway between the bottom of your lowest rib and the top of your hip bone. (Some guides use the navel; be consistent.)
- Hips: around the widest part of your buttocks.
Measure twice and use the average. Units can be inches or centimeters.
Limits
The WHO cutoffs were based mainly on people of European descent; lower cutoffs are often recommended for South Asian, Chinese and Japanese adults. The waist-to-height categories apply to adults with a BMI under 35. The measures aren't meant for pregnancy or children.
If your results show increased risk, it's worth discussing with your doctor, who may check blood pressure, blood sugar and cholesterol. You may also want to try the body fat calculator and the BMI calculator. This calculator is informational and not medical advice; your measurements stay in your browser.
Frequently asked questions
What is a healthy waist-to-hip ratio?
According to the WHO, below 0.90 for men and below 0.85 for women. Higher values indicate substantially increased risk.
How do I calculate waist-to-hip ratio?
Divide your waist measurement by your hip measurement, using the same unit for both.
What waist size is too big?
The CDC and NIH flag a waist over 40 inches for men and over 35 inches for nonpregnant women as a sign of higher health risk.
What is the waist-to-height ratio?
Waist divided by height. Keeping it under 0.5, so your waist is less than half your height, is a simple goal for most adults.
Is waist-to-hip ratio better than BMI?
It measures something different: fat distribution. Using both gives a better picture than either alone.
Sources
- WHO: Waist circumference and waist-hip ratio, report of a WHO expert consultation
- NICE NG246 – Overweight and obesity management: identifying and assessing overweight, obesity and central adiposity
Last reviewed: November 14, 2026 · Kitpebble editorial team
Change log
- : Sources expanded; FAQ and content reviewed.
- : Sources expanded; FAQ and content reviewed.
For general information only; not medical advice or a diagnosis. How we write and review our pages