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Waist-to-Height Ratio Calculator

Enter your height and waist circumference to calculate your waist-to-height ratio, compare it with the practical guide of keeping your waist below half your height, and view a central-adiposity reference category.

Your measurements

Measure your waist midway between the bottom of your ribs and the top of your hips, usually just above the belly button. Breathe out naturally and keep the tape level.

This calculator is intended for general adult reference.

Waist-to-height ratio
0.44
Central-adiposity reference category
Healthy central adiposity
Waist as a percentage of height
44%
Waist measurement at half your height
85 cmCorresponds to a waist-to-height ratio of 0.50.
Relative to half-height guide
10 cm below half your height

Screening estimate only. Waist-to-height ratio is a practical estimate of central adiposity and is not a diagnosis. It is generally used alongside BMI for adults with a BMI below 35. It may not be appropriate during pregnancy, for children under 5, or where body shape or fluid balance is substantially affected by a health condition.

For general information only. Consider this result alongside other measures and advice from a qualified healthcare professional where appropriate.

How to use this calculator

  1. Enter your height, and pick its unit — centimetres, metres, feet, inches, or feet and inches.
  2. Enter your waist circumference, in the same range of units, measured midway between the bottom of your ribs and the top of your hips.
  3. Read your waist-to-height ratio, your waist as a percentage of height, the waist measurement at half your height, and the central-adiposity reference category.

This is a screening and reference estimate for general adult use, not a diagnosis. Nothing is submitted anywhere and no measurements are saved by default. The calculation runs in the page as you type, and the link in your address bar carries your figures, so it can be shared or bookmarked.

How is waist-to-height ratio calculated?

Height and waist are converted to the same unit first, then the ratio is the waist divided by the height — so you can enter your height in one unit, such as feet and inches, and your waist in another, such as centimetres, and still get an accurate ratio. A ratio of 0.50 means the waist is half the height. The waist as a percentage of height is the ratio multiplied by 100, and the waist measurement at half height is the height multiplied by 0.5. The reference category uses the unrounded ratio; the ratio shown on screen is rounded for display. The result is a screening and reference estimate and does not diagnose any health condition, and it depends on taking the waist measurement consistently.

Waist-to-height ratio = Waist circumference ÷ Height
  • Waist as a percentage of height = ratio × 100.
  • Waist measurement at half height = height × 0.5 — the waist that corresponds to a ratio of 0.50.

Worked example. At 170 cm with a 75 cm waist, the ratio is 75 ÷ 170 = 0.44 — 44% of height, in the Healthy central adiposity band. The waist measurement at half that height is 170 × 0.5 = 85.0 cm, so a 75 cm waist is 10.0 cm below half your height. At 175 cm with a 100 cm waist, the ratio is 100 ÷ 175 = 0.57 — Increased central adiposity — and 12.5 cm above the 87.5 cm half-height figure for that height.

What do the central-adiposity reference categories mean?

The category is a neutral reference band based on the unrounded ratio, drawn from the Ashwell shape chart (Ashwell & Hsieh, 2005) and the review by Browning, Hsieh & Ashwell (2010). The same boundaries apply to men and women. It is a screening reference, not a diagnosis or a judgement of overall health.

Waist-to-height ratio bands and their reference categories
RatioReference category
Less than 0.40Below standard reference range
0.40 through 0.49Healthy central adiposity
0.50 through 0.59Increased central adiposity
0.60 and aboveHigh central adiposity

Waist-to-height ratio vs. BMI vs. healthy weight range

All three tools use height, but answer different questions. The BMI calculator compares weight to height and classifies the result, with no information about where any weight sits on the body. The healthy weight range calculator turns that same BMI band into a span of weights for your height. This calculator instead compares waist circumference to height, which several studies suggest reflects central adiposity more closely than weight-based measures alone. Waist-to-height ratio and BMI are generally considered together for adults with a BMI below 35.

None of the three is a diagnosis. Used together, they give a broader picture than any one measurement on its own.

Limitations of waist-to-height ratio

  • A single tape measurement can vary with posture, breathing and where exactly it is taken.
  • Intended for general adult reference. It may not be appropriate during pregnancy, for children under 5, or where body shape or fluid balance is substantially affected by a health condition.
  • It is a screening and reference estimate, not a diagnosis, a body-composition assessment, disease-risk prediction or medical advice.

For an estimate based on body composition rather than a single tape measurement, use the body fat percentage calculator. Consider any result alongside advice from a qualified healthcare professional where appropriate.

Frequently asked questions

How do I measure my waist correctly?

Measure midway between the bottom of your ribs and the top of your hips — usually just above the belly button. Stand relaxed, breathe out naturally, and keep the tape level all the way round without pulling it tight. Take the reading at the end of a normal breath out. Measuring at the same point each time matters more than the exact spot, because the ratio is sensitive to where the tape sits.

What does keeping your waist below half your height mean?

It is the practical version of a waist-to-height ratio below 0.50. Multiply your height by 0.5 to get the waist measurement that sits exactly on a ratio of 0.50; a smaller waist means a ratio below 0.50, a larger one means a ratio above it. The same figure works in any unit, as long as height and waist use the same one.

Is waist-to-height ratio a diagnosis?

No. It is a screening and reference estimate of central adiposity — how much weight is carried around the middle. It does not diagnose any condition, measure body fat directly, or tell you whether you are healthy. Treat the category as a reference point to consider alongside other measures and advice from a qualified healthcare professional.

Is this calculator appropriate during pregnancy or for children?

It is intended for general adult reference. Waist-to-height ratio may not be appropriate during pregnancy, for children under 5, or where body shape or fluid balance is substantially affected by a health condition. A child or young person’s measurements should be assessed against age- and sex-specific growth references by a GP or health visitor, not an adult ratio.

Why does BMI below 35 appear in the limitation note?

Waist-to-height ratio is generally used alongside BMI as an extra check on where weight is carried, and that combined use is described for adults with a BMI below 35. At a BMI of 35 or above, a raised waist measurement is already expected, so the ratio adds little, and assessment is better handled directly with a healthcare professional.

How is waist-to-height ratio calculated?

Waist-to-height ratio is waist circumference divided by height, with both figures converted to the same unit first. The calculator also shows the waist as a percentage of height (the ratio multiplied by 100) and the waist measurement at half your height (height multiplied by 0.5).

Does waist-to-height ratio depend on sex?

No. Unlike BMI or waist circumference alone, the reference boundaries for waist-to-height ratio are the same for men and women, so this calculator only needs your height and waist — not your sex.

How is this different from BMI?

BMI compares weight to height and does not show where weight is carried. Waist-to-height ratio compares waist circumference to height instead, which several studies suggest tracks central adiposity more closely. The two are generally considered together for adults with a BMI below 35; neither is a diagnosis.

Why use waist-to-height ratio instead of waist circumference alone?

A waist measurement that is unremarkable for a tall person can be large relative to a short person. Dividing by height accounts for that, so the same reference figure — half your height — applies regardless of how tall someone is.