Is waist-to-height ratio better than BMI?

It is not better so much as different, and the two are usually read together. BMI describes overall size relative to height; waist-to-height describes how much of that size sits around the middle. NICE recommends using waist-to-height ratio alongside BMI for adults with a BMI under 35, precisely because it adds information BMI cannot provide — including for people with high muscle mass, where BMI alone is often misleading.

Where exactly should I measure my waist?

Midway between the bottom of your lowest rib and the top of your hip bone, which is usually a little above the navel. Measure against skin rather than over clothing, stand relaxed, breathe out normally, and keep the tape level and snug without compressing. Taking the measurement the same way each time matters more than taking it in exactly the right place, because a trend is more informative than a single reading.

Why is “keep your waist under half your height” the rule people quote?

Because 0.5 is the top of the band NICE describes as healthy central adiposity, and expressing it as “less than half your height” makes it something you can check with a tape measure and no arithmetic. It is a rounded summary of a band rather than a precise threshold, and the ratio is commonly interpreted as one indicator among several rather than a line with different meanings on either side.

Does this work if I am very muscular?

NICE specifically notes that the bands may be used for adults with high muscle mass, which is where BMI most often misclassifies people. That said, the ratio still cannot tell muscle from fat at the waist itself — a very developed midsection will read the same as a less developed one of the same circumference.

Body MeasurementsGeneral WellnessDiabetes & Metabolic Health

Waist-to-Height Ratio Calculator

Enter your waist measurement and your height to get your waist-to-height ratio, placed in the central adiposity bands NICE publishes for adults. The ratio is unitless, so it is the same whether you measure in centimeters or inches, and it captures something BMI cannot — where body size is carried rather than only how much there is.

Updated September 29, 2026

How we calculate it

Waist-to-height ratio = waist circumference ÷ height (same unit for both)

Waist-to-height ratio is your waist circumference divided by your height, with both measured in the same unit. Because the units cancel, the result is a plain number that reads identically in centimeters or inches. NICE publishes bands for adults in guideline NG246: 0.4 to 0.49 is described as healthy central adiposity, 0.5 to 0.59 as increased central adiposity, and 0.6 or above as high central adiposity, with a ratio below 0.4 noted as a possible indication of being underweight. NICE states these bands may be used for adults of both sexes and all ethnicities who have a BMI under 35 kg/m², including adults with high muscle mass — which is the main reason the ratio is useful alongside BMI rather than instead of it. The measurement protocol matters more than the arithmetic: NICE and the WHO both describe measuring midway between the lowest rib and the top of the hip bone, against skin, at the end of a normal breath out, with the tape snug but not compressing. Measuring at the navel instead, or after a large meal, can move the result by a whole band.

Important limitations

The result depends almost entirely on where the tape is placed. Measuring at the navel rather than midway between the lowest rib and the hip bone can shift the ratio by a whole band.
NICE applies these bands to adults with a BMI under 35 kg/m². Above that they are not used, because waist measurement adds little once central adiposity is already established.
The bands are not validated for children or adolescents, who are assessed against age- and sex-specific charts, and they are not used during pregnancy.
A fixed ratio cut-point has been criticized for penalizing shorter adults and being lenient with taller ones, because waist, height and body fat are not perfectly proportional to one another.
The ratio describes body shape, not its cause. It cannot distinguish abdominal fat from a broad frame, muscle, bloating or fluid.
This is a screening measurement. It is not a diagnosis, and on its own it says nothing about blood pressure, blood sugar or cholesterol.

Frequently asked questions

Sources

This page is based on the following sources. Each was reviewed on the access date shown.

Overweight and obesity management: identifying and assessing overweight, obesity and central adiposity (NG246)(opens in a new tab)
National Institute for Health and Care Excellence (NICE)
Clinical guidelinePublished January 14, 2025Accessed September 27, 2026
Waist circumference and waist-hip ratio: report of a WHO expert consultation, Geneva, 8-11 December 2008(opens in a new tab)
World Health Organization
Clinical guidelinePublished January 1, 2011Accessed September 27, 2026
A healthy lifestyle — WHO recommendations(opens in a new tab)
World Health Organization
Government health agencyAccessed September 27, 2026

Medical disclaimer. Gravis Labs provides general educational information and calculation tools. Results may be estimates and are not a medical diagnosis or a substitute for professional medical advice, clinical examination, clinical judgment, or treatment.

In an emergency. Do not use Gravis Labs for medical emergencies. If you believe you are experiencing a medical emergency, contact your local emergency services or seek urgent medical care.

Scope. Gravis Labs is an information and calculation service. It is not a medical device, and it is not registered, approved, certified or cleared by any medical regulator or health authority. Nothing here carries clinical authority: every result is an estimate produced by a published equation, and anything that matters for your health needs the opinion of a qualified clinician who can examine you and see your full history.

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