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Waist-to-hip ratio calculator (WHR)

Calculate an adult waist-to-hip ratio from waist and hip circumferences measured in the same selected unit, without diagnosing, classifying health risk, assigning a body shape or setting a personal target.

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Calculate your result

Measure midway between the lower margin of the last palpable rib and the top of the iliac crest, at the end of a normal breath out. Use the selected unit, no thousands separator and no more than one decimal place.

Accepted range: 20 to 400 cm

Measure horizontally around the maximum circumference over the buttocks. Use the same selected unit as the waist, no thousands separator and no more than one decimal place.

Accepted range: 20 to 400 cm

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What this result means

Waist-to-hip ratio is waist circumference divided by hip circumference. When both measurements use the same unit of length, that unit cancels in the ratio. [1][2]

How to measure waist and hips consistently

Stand upright with arms relaxed. For waist circumference, place a non-stretch tape horizontally midway between the lower margin of the last palpable rib and the top of the iliac crest. Keep it snug without compressing tissue and read it at the end of a normal breath out. [1][2]

For hip circumference, keep the tape horizontal around the maximum circumference over the buttocks without compressing tissue. Repeat both measurements with the same landmarks, posture, clothing conditions and tape tension. If a clinician, survey or programme gave you another protocol, do not silently combine measurements from different methods. [1][2][6]

What the ratio and percentage mean

A ratio of 0.800 means the waist measurement is 0.8 times the hip measurement. The equivalent 80.0% expresses the same arithmetic as a percentage. It is not body-fat percentage and does not show why either circumference has its value. [1]

Centimetres and inches produce the same ratio when both fields use the same unit because that unit cancels in the division. One international inch is exactly 2.54 centimetres; the calculator does not need to convert the ratio itself. [7]

Why this result has no health-risk label

The WHO consultation discusses population reference points alongside differences in sex, age, ethnicity, measurement method and risk evidence. Those population associations are not a universal personal diagnosis, so this calculator does not apply an automatic band at any value. [1]

Sex and gender are not inputs to the division itself. Asking for either solely to calculate the ratio would add no arithmetic value, and using a sex-specific historical reference point here could be mistaken for an individual health classification. [1]

Current UK, Australian and Canadian guidance places body measurements inside wider eligibility and assessment rules rather than establishing one worldwide consumer waist-to-hip category. A qualified professional can interpret measurements in the appropriate local and personal context when needed. [3][4][5][6]

Waist-to-hip and waist-to-height are different ratios

Waist-to-hip ratio divides waist circumference by hip circumference. Waist-to-height ratio divides waist circumference by standing height. The denominator, measurement protocol and interpretation evidence differ, so a value or category from one ratio must not be applied to the other. [1][3]

What can affect a repeat measurement

Tape placement, tightness, posture, breathing and clothing can move either circumference. A different waist landmark or hip tape angle can also produce a different ratio, so a small change should not automatically be treated as a body change. [1][2][6]

The displayed ratio and percentage are rounded outputs from the values entered. They do not provide a confidence interval, estimate measurement error or show whether a difference is medically important.

Safe next steps

If you want to repeat the calculation, record both landmarks and use the same tape method, clothing conditions and unit. If the result worries you, you cannot use the protocol safely, or an exclusion applies, discuss the measurements in context with a qualified health professional rather than acting on this ratio alone. [1][2]

Formula and assumptions

Formula
WHR = W ÷ H; % = WHR × 100 [1][2]
Version
Adult waist-to-hip ratio, adult-raw-waist-to-hip-ratio-v1
Rounding
Use exact decimal arithmetic. Round the ratio once to three decimal places and the percentage independently from the same unrounded values to one decimal place, using half-up rounding. The supported 0.1-unit input resolution does not imply clinical precision.
Worked example
A waist circumference of 80 cm and a hip circumference of 100 cm give 80 ÷ 100 = 0.8. The ratio displays as 0.800. Calculated independently from the same unrounded values, the equivalent percentage is 80.0%. This arithmetic is not a personal health-risk or body-shape label.

Who this is for — and when not to use it

Intended use

Neutral general-wellness arithmetic for adults aged 18 and over who have waist and hip circumferences measured in the same selected unit with the stated protocol and want the raw ratio and equivalent percentage only.

Not intended for

This tool does not calculate waist-to-height ratio, BMI or body-fat percentage; assign a sex-based category or body shape; diagnose central adiposity or any condition; classify personal health risk; decide whether a result is healthy, high, low or optimal; set a target; or guide weight-loss, diet, exercise, medication, supplement or treatment decisions.

Exclusions

  • Children and adolescents under 18; anthropometric interpretation requires age- and development-appropriate assessment
  • Pregnancy, postpartum or lactation-related body-change interpretation
  • A diagnosed or suspected eating disorder, or use as a body-checking or body-target tool
  • Ascites, abdominal distension, oedema, a major abdominal mass or another condition that materially changes a circumference
  • Recent abdominal or hip surgery, severe pain, or a situation in which either measurement is unsafe or medically restricted
  • Inability to stand or maintain the stated external tape-measure protocol
  • Growth, skeletal, spinal, limb-loss or other anatomy that makes the protocol non-comparable without specialist assessment
  • Measurements taken in different units, at different landmarks or with different tape protocols
  • Text, ranges, inequality signs, grouping separators or a unit typed into a numeric field
  • Diagnosis, personal cardiovascular or metabolic risk scoring, treatment decisions, body-shape labelling or target setting

Evidence sources

  1. 1. Waist circumference and waist–hip ratio: report of a WHO expert consultation — World Health Organization. Accessed Aug 17, 2026.
  2. 2. WHO STEPS surveillance manual — World Health Organization. Accessed Aug 17, 2026.
  3. 3. Identifying and assessing overweight, obesity and central adiposity — NICE guideline NG246 — National Institute for Health and Care Excellence. Accessed Aug 17, 2026.
  4. 4. Calculate your waist to height ratio — National Health Service. Accessed Aug 17, 2026.
  5. 5. Body mass index (BMI) and waist measurement — Australian Government Department of Health, Disability and Ageing. Accessed Aug 17, 2026.
  6. 6. Canadian Guidelines for Body Weight Classification in Adults — Quick Reference Tool for Professionals — Health Canada. Accessed Aug 17, 2026.
  7. 7. NIST Guide to the SI, Appendix B: Conversion Factors — National Institute of Standards and Technology. Accessed Aug 17, 2026.