Your waist-to-hip ratio is your waist measurement divided by your hip measurement. The World Health Organization treats a ratio of 0.85 or above in women, and 0.90 or above in men, as a sign of increased health risk because it suggests more fat is carried around the middle. A woman with an 82 cm waist and 100 cm hips has a ratio of 0.82, which is below the threshold.
Note: this is general information, not medical advice. A waist-to-hip ratio is a screening guide, not a diagnosis. If you are worried about your weight, shape or health, talk to a GP, practice nurse or pharmacist, and check the NHS website for current advice.
What the waist-to-hip ratio measures
The ratio compares two measurements to describe where your body stores fat. Fat carried around the abdomen, sometimes called central or visceral fat, is linked in medical research with a higher risk of conditions such as type 2 diabetes and heart disease than fat stored on the hips and thighs. A body shape with a larger waist than hips is often described as “apple-shaped”, and one with larger hips as “pear-shaped”.
The formula is simple:
Waist-to-hip ratio = waist circumference ÷ hip circumference
Both measurements must be in the same units, so centimetres or inches, and the ratio itself has no units. A waist of 82 cm and hips of 100 cm give 82 ÷ 100 = 0.82. The same person measured in inches, 32.3 and 39.4, gives the same result, because the units cancel out.
Unlike BMI, the ratio does not use your weight or height. That is its strength and its weakness: it tells you about shape, not about whether your weight is in a healthy range.
How to measure your waist and hips
Accuracy matters, because a 2 cm error moves the ratio by about 0.02, which is enough to change which side of a threshold you land on. Follow these steps:
- Stand up straight, relaxed, with your feet together and your arms by your sides. Measure over bare skin or thin clothing.
- Waist: find the midpoint between the bottom of your lowest rib and the top of your hip bone, on the side of your body. Wrap the tape around your middle at that level, keeping it level with the floor. Breathe out normally and read the measurement without pulling the tape tight.
- Hips: measure around the widest part of your buttocks, with the tape level all the way round.
- Take each measurement twice. If the two readings differ, take a third and use the average.
Do not measure your waist at your belly button or your trouser waistband, because both vary from person to person. If someone else can help you hold the tape level, the reading is more accurate. Measure at the same time of day, because a large meal or bloating can add a centimetre or two.
The WHO thresholds: what the numbers mean
The WHO expert consultation on waist circumference and waist-hip ratio uses these cut-offs for abdominal obesity:
| Below the threshold | At or above the threshold | |
|---|---|---|
| Women | Under 0.85 | 0.85 or above |
| Men | Under 0.90 | 0.90 or above |
Being at or above the threshold does not mean you have a disease. It means the ratio is consistent with increased health risk compared with a lower figure, and that it may be worth discussing your lifestyle and health checks with a professional. Being below it does not guarantee good health, because other factors, including blood pressure, cholesterol, smoking, family history and activity levels, matter too.
You may also see waist circumference given on its own. Commonly quoted figures are 94 cm for men and 80 cm for women for increased risk, and 102 cm and 88 cm for substantially increased risk. Check the NHS website for the guidance it currently gives, because advice can differ for different groups.
Worked examples with the calculator
Here are example measurements run through the House of Calculator waist-to-hip tool, with the height used to work out the waist-to-height ratio as well:
| Person | Waist | Hips | Height | Ratio | Against WHO threshold | Waist-to-height |
|---|---|---|---|---|---|---|
| Woman A | 82 cm | 100 cm | 168 cm | 0.82 | Below 0.85 | 0.49 |
| Woman B | 88 cm | 98 cm | 165 cm | 0.90 | At or above 0.85 | 0.53 |
| Woman C | 74 cm | 104 cm | 172 cm | 0.71 | Below 0.85 | 0.43 |
| Man D | 86 cm | 100 cm | 180 cm | 0.86 | Below 0.90 | 0.48 |
| Man E | 98 cm | 102 cm | 178 cm | 0.96 | At or above 0.90 | 0.55 |
| Man F | 104 cm | 108 cm | 175 cm | 0.96 | At or above 0.90 | 0.59 |
Look at Man E and Man F: they have the same ratio of 0.96, but their waists are 6 cm apart and their waist-to-height ratios differ, 0.55 against 0.59. That is a reminder that the ratio can hide differences. A larger man with proportionally larger hips can score the same as a smaller one with a bigger waist, which is why a waist measurement or waist-to-height ratio is useful alongside it.
Man D shows the opposite. His ratio is 0.86, which is under the 0.90 threshold, and his waist is under half his height, so both signs are reassuring.
If you use inches, the result is the same. A woman with a 32-inch waist and 40-inch hips has a ratio of 0.80, and at 65 inches tall, a waist-to-height ratio of 0.49.
Waist-to-hip ratio compared with BMI
BMI is weight in kilograms divided by height in metres squared. The NHS ranges for adults are under 18.5 underweight, 18.5 to 24.9 healthy, 25 to 29.9 overweight and 30 and above obese. BMI explained: what it tells you and what it doesn't covers it in full. BMI is quick and needs no tape measure, but it cannot tell fat from muscle and does not show where the fat is.
Consider two women who are both 168 cm tall and weigh 65 kg. Each has a BMI of 65 ÷ (1.68 × 1.68) = 23.0, which is in the healthy range. One has a waist of 74 cm and hips of 104 cm, a ratio of 0.71. The other has a waist of 88 cm and hips of 98 cm, a ratio of 0.90. Their BMI is identical, but their body shapes, and the amount of fat carried around the middle, probably differ. The ratio picks up that difference where BMI does not.
The reverse can also be true. Someone with a lot of muscle may have a high BMI but a low waist-to-hip ratio. For that reason, health professionals often look at several measures together rather than relying on one. If you want to understand body composition more directly, Body fat percentage: how it's measured and what's typical explains other methods and their limits.
The waist-to-height ratio: a simple companion
The NHS advises keeping your waist to less than half your height. To check, divide your waist by your height, in the same units. A 168 cm woman with an 82 cm waist has 82 ÷ 168 = 0.49, which is under 0.5. The tool also gives the cut-off directly: for 168 cm the waist should be 84 cm or under.
This measure has an advantage: you do not need the hip measurement, and it adjusts for height. It also gives a clear target. If your ratio is 0.55 and you are 178 cm, your waist is 98 cm, and a waist under 89 cm would be below half your height. That means losing about 9 cm from the waist, which is a useful goal to discuss with a health professional, not a target to chase at any cost.
Limits and groups for whom the ratio is less reliable
Waist-to-hip ratio is a screening tool, and it has weaknesses:
- Different ethnic groups. Risk thresholds can differ for people of South Asian, Black and other minority ethnic backgrounds, who may face higher risk at lower waist sizes. The NHS notes lower thresholds for some groups in its BMI advice, so check current guidance.
- Pregnancy. The ratio is not meaningful when the abdomen is growing for a baby.
- Older adults. Height loss, changes in posture and fat distribution make the ratio less reliable.
- Children and teenagers. The adult cut-offs do not apply. Children’s measurements are interpreted on growth charts.
- Muscle, bone structure and body shape. A wide pelvis or strong hips can lower the ratio without changing health risk, and a very narrow frame can raise it.
- Medical conditions and medicines. Some conditions cause fluid or fat changes in the abdomen that affect measurements.
- Measurement error. Small differences in tape position change the result.
For these reasons the ratio is one piece of information, not a verdict. It does not diagnose anything.
What to do with your result
If your ratio is below the threshold, there is nothing special to do, and you can use it to track change over time. If it is at or above the threshold, consider these steps:
- Re-measure on another day to check the figures.
- Talk to a GP or practice nurse, who can look at blood pressure, cholesterol and blood sugar, and advise on next steps. The NHS Health Check is offered in England to some adults, so check whether you are eligible.
- Think about the general habits that affect health: regular physical activity, balanced eating, sleep, alcohol and smoking. Calories and TDEE: how many calories do you need? explains how energy intake and activity affect weight, if weight loss is a goal your health professional supports.
- Set sensible, gradual goals rather than fast changes. A waist reduction of a few centimetres is meaningful.
Do not use the ratio to judge your body or anyone else’s. If measuring leads to anxiety or unhealthy eating, stop and speak to a professional. Support is available through your GP and organisations such as Beat for eating disorders.
Try the calculator
Enter your waist, hips, sex and height in the Waist-to-Hip Ratio Calculator to see your ratio, how it compares with the WHO threshold and your waist-to-height ratio. Measure carefully, and take the result as a prompt for a conversation, not a diagnosis.
Frequently asked questions
What is a healthy waist-to-hip ratio?
The WHO treats a ratio under 0.85 for women and under 0.90 for men as below the level that indicates increased risk. Lower ratios generally mean less fat carried around the middle, but the ratio is only a guide.
How do I measure my waist and hips for the ratio?
Measure your waist halfway between the bottom of your ribs and the top of your hip bones, and your hips at the widest part of your buttocks. Use a flexible tape, keep it level and breathe out normally. Take each measurement twice.
Is waist-to-hip ratio better than BMI?
They measure different things. BMI relates weight to height, while the ratio shows where fat is stored. Many professionals use both, along with waist circumference or waist-to-height ratio, because each has limits.
Does a high ratio mean I have a health problem?
Not by itself. It indicates higher risk, but it does not diagnose anything. Blood pressure, cholesterol, blood sugar, family history and lifestyle matter too, so discuss it with a health professional.
Can I change my waist-to-hip ratio?
For many people, a smaller waist comes with regular activity, a balanced diet and healthy weight loss, if that is appropriate for you. Hip size and bone structure are largely fixed, so focus on the waist and your overall health.