How to measure your waist
Stand up, find the lowest rib you can feel and the top of your hip bone, and put the tape halfway between them. Keep it level all the way round, snug but not pressing in. Breathe out normally and read it before you breathe in again. Measure twice and average.
The six steps
Find the two bones
Stand up and run your fingers down your side. The first landmark is the lowest rib you can feel. The second is the top of your hip bone, the ridge you find if you keep going down and press in. The WHO measures halfway between the two.
Stand properly
Feet close together, arms hanging at your sides, weight even on both feet. Wear as little as you reasonably can over the spot, because a jumper adds centimetres that are not yours. Do not lean, and do not look down at the tape, which pulls your posture forward.
Put the tape where it belongs
Wrap it around, level with the floor the whole way round. This is the part people get wrong at the back, where the tape rides up without you seeing it. A mirror helps more than a second pair of hands.
Snug, not tight
The tape should sit against your skin without pressing into it. If you can see the skin bulging above or below the tape, it is too tight. Research protocols use a tape with a spring that holds exactly 100 grams of tension, precisely because people pull too hard.
Breathe out, then read it
Take a normal breath in, let it out, and read the tape at the end of that breath, before you inhale again. Do not force the air out and do not hold your breath. And do not pull your stomach in: tensing your abdominal wall makes the number smaller without making you smaller.
Do it twice
The WHO protocol says to take the measurement twice. If the two readings are within a centimetre of each other, average them and that is your number. If they are more than a centimetre apart, take both again, because one of them went wrong.
The awkward part: there is more than one right place
Most articles tell you to measure your waist as though everyone agrees where that is. They do not. The major health bodies publish different protocols, and they measure at different heights on your body.
The WHO protocol, used in its STEPS surveillance programme worldwide, measures at the midpoint between the lower margin of the last palpable rib and the top of the iliac crest. The US National Institutes of Health guide and the NHANES survey measure at the top of the iliac crest, which is lower. A third protocol, used in the Multi-Ethnic Study of Atherosclerosis, measures at the navel, and published work found that measuring there can underestimate waist circumference.
This matters more than it sounds. The cut points you will read everywhere, 94 cm and 102 cm for men, 80 cm and 88 cm for women, came out of work using the higher measurement. Measure somewhere else and you are comparing your number against a threshold built from a different one.
What to actually do about it. Use the WHO point, the midpoint between rib and hip bone, because that is where the published guidance comes from. Then use the same point every single time. For watching your own number move over months, consistency beats choosing correctly; for reading it against a published threshold, the landmark matters.
The five things that go wrong
| Mistake | What it does |
|---|---|
| Measuring over clothes | Adds whatever the fabric adds, which can be several centimetres in a jumper and is not consistent between measurements. |
| Pulling the tape tight | Compresses the skin and shrinks the number. Research tapes hold a fixed 100 g of tension for exactly this reason. |
| Sucking your stomach in | Tensing the abdominal wall reduces the measurement. It does not reduce anything else. |
| Holding your breath | Both a held inhale and a forced exhale move the number. Read at the end of an ordinary breath out. |
| Using your trouser size | A garment measurement, inconsistent between brands, and usually taken lower on the body than any health protocol. |
What the number means
On its own, not very much. Waist circumference gets useful when you put it next to your height, because a 90 cm waist means something different on someone who is 1.60 m and someone who is 1.90 m.
Waist to height ratio outperformed both waist circumference and BMI as a screening tool for cardiometabolic risk factors in a systematic review and meta-analysis, and the rule fits in one line: keep your waist under half your height.
The absolute thresholds, and the caveat nobody quotes
These are the figures you will find everywhere, from the WHO's own table:
| Measurement | Men | Women | Described as |
|---|---|---|---|
| Waist circumference | Over 94 cm | Over 80 cm | Increased risk |
| Waist circumference | Over 102 cm | Over 88 cm | Substantially increased risk |
| Waist to hip ratio | 0.90 or above | 0.85 or above | Substantially increased risk |
Here is the part almost nobody repeats. The WHO expert consultation report that publishes that table says in the same document that those sex-specific cut-off points were an example only and not WHO recommendations. They come from a single study of about 2,200 men and 2,700 women in the Netherlands. They are widely used, they are reasonable, and they are not the law of nature the internet treats them as.
There is a second caveat with more practical bite. The International Diabetes Federation publishes thresholds that depend on population: over 94 cm for European men and over 80 cm for European women, but over 90 cm for South Asian, Chinese and Japanese men. If that describes you, the commonly quoted male figure is set too high.
Which is the same point this whole site keeps making. A number is only as good as the method behind it, and you are entitled to know what that method was.
Common questions
Where exactly do you measure your waist?
The World Health Organization measures at the midpoint between the lowest rib you can feel and the top of your hip bone. For most people that is a little above the navel. The US National Institutes of Health and the NHANES survey use a different point, the top of the hip bone itself, which sits lower. A third protocol uses the navel. They are all in use and they give different numbers, so the important thing is to pick one, know which one it is, and use it every time.
Is your waist measurement the same as your trouser size?
No, and usually not close. Trouser sizing is a garment measurement, it varies between brands, and jeans are normally worn below the point any health protocol measures at. People are often several centimetres out when they use their trouser label. Use a tape.
Should I measure at the navel or above it?
Above it, if you want to compare your number with published health guidance, because the WHO protocol measures at the midpoint between the lowest rib and the hip bone and that usually sits above the navel. The navel is used by some research protocols, and published work has found that measuring there can underestimate waist circumference. It is a defensible place to measure as long as you always use it and you know the cut points were not built on it.
Should I breathe in or out when measuring my waist?
Out, and normally. The protocol is to read the tape at the end of a normal breath out, which is when your lungs are at rest. Holding a big breath in, forcing all the air out, or sucking your stomach in all change the number, and none of them changes you.
What is a healthy waist measurement?
The figures usually quoted are 94 cm for men and 80 cm for women as raised risk, and 102 cm and 88 cm as substantially raised. Read the section below before you use them: the WHO's own report describes those numbers as an example based on one Dutch study rather than a WHO recommendation, and the International Diabetes Federation publishes lower thresholds for South Asian, Chinese and Japanese populations.
Sources
Every figure above comes from one of these. Check them.
- World Health Organization (2011). Waist circumference and waist-hip ratio: report of a WHO expert consultation, Geneva, 8 to 11 December 2008
- World Health Organization (2008). WHO STEPwise approach to surveillance (STEPS), Section 5: physical measurements
- NHLBI Obesity Education Initiative (2000). The practical guide: identification, evaluation and treatment of overweight and obesity in adults. NIH Publication 00-4084
- Ashwell M, Gunn P, Gibson S (2012). 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 13(3), 275-286
- Alberti KGMM, Zimmet P, Shaw J (2006). Metabolic syndrome: a new world-wide definition. A consensus statement from the International Diabetes Federation. Diabetic Medicine 23(5), 469-480
- NICE guideline NG246 (2025). Overweight and obesity management
One waist measurement, four different readings of it
Enter it once and the app reads it four ways, waist to height and waist to hip among them, each one naming the method it used.
Free, no account, and it works offline. 100,000+ downloads on Google Play.
This is not medical advice. Body Numbers is a calculator. It does not diagnose, treat or monitor any condition, and no number it produces should replace a conversation with a doctor or a dietitian. If a result worries you, or if you are pregnant, unwell, or under eighteen, speak to a health professional.
