Your waist-to-hip ratio (WHR) is your waist measurement divided by your hip measurement, and the World Health Organization (WHO) links a ratio above 0.90 in men and 0.85 in women to substantially increased cardiometabolic risk. Because it divides two lengths measured in the same unit, WHR is unitless: measure both in centimetres or both in inches and you get the same number. A man with a 96 cm (38 in) waist and 100 cm (39 in) hips has a WHR of 0.96; a woman with an 80 cm (31.5 in) waist and 100 cm (39 in) hips has a WHR of 0.80. This guide explains where those cut-offs come from, why fat around your middle matters more than fat on your hips, and how WHR compares with BMI, waist circumference and waist-to-height ratio. It is general information, not medical advice.
What waist-to-hip ratio measures
WHR captures the shape of your body rather than its overall size. Two people can weigh the same and share the same body mass index yet carry that weight very differently: one storing fat around the abdomen (an "apple" shape), the other around the hips and thighs (a "pear" shape). WHR puts a number on that difference. A higher ratio means proportionally more of your girth sits at the waist relative to the hips, which acts as a proxy for how much fat is packed around your central organs.
The formula is simply waist divided by hip. To skip the arithmetic and read your result against the risk bands automatically, you can calculate your waist-to-hip ratio from two tape-measure readings. What makes the number useful is not the girth itself but what a high ratio signals about where your body stores fat, which is information a scale or a BMI figure cannot give you.
WHO cut-offs and the low, moderate and high bands
Drawing on its 2008 expert consultation on waist circumference and waist-hip ratio, the WHO sets the threshold for "substantially increased" cardiometabolic risk at a WHR above 0.90 for men and above 0.85 for women. The cut-offs differ by sex because women naturally carry more fat on the hips and thighs, which lowers a typical woman's ratio for the same amount of abdominal fat.
Many clinicians and fitness bodies, including the American College of Sports Medicine (ACSM), use a more detailed set of bands that split risk into low, moderate and high:
| Sex | Low risk | Moderate risk | High risk |
|---|---|---|---|
| Men | 0.90 or below | 0.91 - 0.95 | 0.96 or above |
| Women | 0.80 or below | 0.81 - 0.85 | 0.86 or above |
Waist-to-hip ratio risk bands by sex, based on WHO cut-offs and the classification used by the American College of Sports Medicine. Bands describe population-level cardiometabolic risk, not an individual diagnosis, and specific boundaries shift somewhat with age.
The two systems line up: the WHO's 0.90 line for men sits at the top of the low-risk band, and the 0.85 line for women does the same. A man at 0.93 or a woman at 0.83 falls into the moderate band, an amber signal rather than a diagnosis. These are population averages for adults, not figures tuned to any one person's build, and a single reading matters far less than a rising trend over months.
Why central fat is riskier than hip and thigh fat
WHR predicts health outcomes because of what kind of fat sits at the waist. Abdominal girth reflects two things: subcutaneous fat just under the skin, and visceral fat, the deeper fat wrapped around the liver, pancreas and intestines. Visceral fat is metabolically active in ways that hip and thigh fat is not.
- It drains straight to the liver. Fat around the organs releases free fatty acids and signalling molecules directly into the portal vein that feeds the liver, which can drive up blood sugar, blood fats and insulin resistance.
- It behaves like an active organ. Visceral fat secretes inflammatory compounds linked to type 2 diabetes, high blood pressure and cardiovascular disease. The international INTERHEART study, which examined 27,000 people across 52 countries and was published in The Lancet in 2005, found waist-to-hip ratio to be a far stronger predictor of heart-attack risk than BMI.
- Hip and thigh fat may be protective. Fat stored on the lower body (the "pear" pattern) is more inert and, in some research, is associated with a modestly lower metabolic risk, which is one reason the same amount of total fat can be less harmful when it sits below the waist.
This is why a high WHR is worth heeding even when your weight looks fine on paper: it flags the fat depot most closely tied to disease, which whole-body measures average away.
WHR versus BMI, waist circumference and waist-to-height
WHR is one of several tape-and-scale measures, and each answers a slightly different question. Used together, they give a far clearer read than any one alone.
- BMI reflects overall weight relative to height. It is a useful population screen but cannot tell muscle from fat or see where fat sits, so a muscular person can score "overweight" with a perfectly healthy waist. To see your own figure, use the BMI calculator and read it alongside your waist, not instead of it.
- Waist circumference measures central fat directly, without a hip reading. The CDC and WHO flag substantially increased risk above 102 cm (40 in) for men and 88 cm (35 in) for women. Its advantage over WHR is that it is not "diluted" by hip size, since large hips can mask a large waist in the ratio.
- Waist-to-height ratio divides waist by height, with a simple rule of thumb from NICE: keep your waist under half your height, a ratio below 0.5. It works across different heights and, for many people, flags central-fat risk earlier than BMI does.
- Body-fat percentage estimates how much of your weight is fat overall. A body fat calculator approximates it from a few measurements, which helps most when your BMI sits near a category boundary or you are more muscular than average.
A practical way to combine them: BMI for a quick size check, waist circumference or waist-to-height for how much fat sits centrally, WHR for your overall fat-distribution pattern, and body-fat percentage for composition. When several agree, you can trust the signal; when they disagree, as they often do for very lean or very muscular people, the disagreement itself is useful information.
How to measure waist-to-hip ratio correctly
WHR is only as good as the two measurements behind it, and small errors in placement change the ratio noticeably. Use a flexible, non-stretch tape over bare skin or thin clothing, standing relaxed with your feet together.
- Waist: measure around the narrowest part of your torso, roughly midway between the lowest rib and the top of the hip bone (near or just above the navel for most people). Breathe out gently and take the reading at the end of a normal exhale; don't suck in or push out. Keep the tape snug and level all the way around, without compressing the skin.
- Hips: measure around the widest part of your buttocks, keeping the tape horizontal. Use a mirror or your phone to check the tape is level at the back.
Take each measurement two or three times, use the average, and measure at the same time of day for consistency. Then divide waist by hip. If your waist is 84 cm (33 in) and your hips are 102 cm (40 in), your WHR is 84 divided by 102, which rounds to 0.82. Because both figures are in the same unit, the answer is identical whether you work in centimetres or inches.
The limits of waist-to-hip ratio
WHR is a helpful screening figure, but it has clear blind spots and does not apply to everyone.
- Pregnancy. Waist and hip measurements change dramatically during pregnancy and the postpartum period, so WHR is not a meaningful health indicator at these times.
- Very muscular builds. Well-developed hip and glute muscles enlarge the hip measurement, which can push the ratio down and understate central fat, just as a very lean, narrow-hipped athlete can read high without excess visceral fat.
- Children and teenagers. The adult cut-offs do not apply to anyone still growing; body proportions shift with age, and paediatric assessment uses growth-reference data, not fixed adult bands.
- A large waist hidden by large hips. Because it is a ratio, a genuinely high waist can be masked by proportionally large hips, keeping the number "normal." This is exactly why waist circumference on its own is a useful companion measure.
- Ethnic differences. Some populations, including many people of South and East Asian heritage, carry higher metabolic risk at lower thresholds, so standard cut-offs may understate their risk.
Treat WHR as one input among several, not a verdict. If your ratio sits in the moderate or high band, use it as a prompt to look at your waist size, activity, diet, blood pressure, blood sugar and family history, and to raise it with a qualified health professional who can weigh these numbers against your full picture. Track the trend across months rather than fixating on a single reading, since day-to-day girth shifts with food, fluid and salt. These tools are meant to inform that conversation, not replace it.
Key sources: World Health Organization 2008 expert consultation on waist circumference and waist-hip ratio; U.S. CDC and NHS guidance on waist measurement and healthy weight; NIH/NHLBI reports on body composition and cardiometabolic risk; NICE guidance on waist-to-height ratio; American College of Sports Medicine (ACSM) risk classification; and the INTERHEART study (Yusuf et al., The Lancet, 2005). See the full source list below. This article is general information, not a substitute for personalised medical advice.