- Measure halfway between the bottom of your lowest rib and the top of your hip bone — often around the belly button, not your trouser line.
- Breathe out normally and keep the tape snug but not tight.
- Compare it with your height: a waist below half your height is the healthy target.
What you need
A flexible tape measure and a mirror. Measure on bare skin or over a single thin layer, ideally first thing in the morning before eating.
Step by step
- Stand up straight with your feet together and your stomach relaxed.
- Find the bottom of your lowest rib and the top of your hip bone on one side.
- Place the tape halfway between the two — for many people this is around the belly button.
- Wrap the tape around your body, keeping it level all the way round (check in the mirror).
- Breathe out normally and read the measurement at the end of the breath. Don’t pull your stomach in.
- Measure twice. If the readings differ by more than 1 cm, measure a third time and use the average of the two closest.
Common mistakes
- Measuring at the narrowest point or at your trouser waistband, which is often lower.
- Pulling the tape tight enough to dent the skin.
- Holding your breath or sucking your stomach in.
- Letting the tape drop at the back.
What your number means
The simplest guide is to keep your waist to less than half your height — a waist-to-height ratio below 0.5. You may also see fixed cut-offs, which the NHS has used for adults: a waist of 94 cm (37 in) or more for men, or 80 cm (31.5 in) or more for women, suggests increased risk; 102 cm (40 in) for men and 88 cm (34.5 in) for women suggests high risk.
Tracking your progress
Measure once a month, at the same time of day, in the same place. Your waist often shrinks while the scales stand still — especially when you are building muscle — so it is a motivating number to keep alongside your BMI.
Not sure if medical weight loss is right for you?
Our free online assessment takes about five minutes. A GPhC-registered prescriber reviews it and only recommends treatment if it is safe and suitable for you.
Start the free assessmentFrequently asked questions
Should I measure over clothes?
Bare skin is best. A single thin layer is fine, but thick clothing can add several centimetres.
My waist went down but my weight didn’t — is that progress?
Yes. Losing central fat while gaining or keeping muscle is a real health improvement, even if the scales barely move.
Why is my measurement bigger than my jeans size?
Clothing sizes vary by brand and most trousers sit below the true waist, so a tape measure at the correct point usually reads higher.
This page is general health information. It does not replace advice from your GP or another healthcare professional who knows your history. If you have symptoms that worry you, contact your GP or NHS 111; in an emergency call 999. Prescription treatment is only supplied after an assessment by a registered prescriber.