Waist-to-hip ratio compares the circumference of your waist with the circumference of your hips. A higher ratio means more of your fat sits around the abdomen rather than the hips and thighs — the pattern linked to metabolic disease. The World Health Organization uses a single cut-off for each sex: 0.90 for men and 0.85 for women.
- Formula
- Waist ÷ hip, in the same units
- WHO cut-off, men
- 0.90 and above — substantially increased risk
- WHO cut-off, women
- 0.85 and above — substantially increased risk
- What it reflects
- Fat distribution, not total body fat
- Source
- WHO Expert Consultation, Geneva, December 2008
Formula
WHO Expert Consultation (2008) cut-offsWaist-to-hip ratio = waist circumference ÷ hip circumference
- waist
- — Measured at the midpoint between the lower margin of the last palpable rib and the top of the iliac crest (hip bone)
- hip
- — Measured around the widest portion of the buttocks
Both measurements are lengths, so the units cancel — inches over inches gives the same ratio as centimetres over centimetres. The classification uses the WHO 2008 expert consultation, which defines one sex-specific threshold for substantially increased risk of metabolic complications rather than a graded scale.
Waist-to-Hip Ratio examples
| Input | Result | Category |
|---|---|---|
| Man, 34" waist, 40" hips | 0.85 | Not increased |
| Man, 38" waist, 40" hips | 0.95 | Substantially increased risk |
| Man, 42" waist, 41" hips | 1.02 | Substantially increased risk |
| Man, 95 cm waist, 100 cm hips | 0.95 | Substantially increased risk |
| Woman, 28" waist, 38" hips | 0.74 | Not increased |
| Woman, 32" waist, 39" hips | 0.82 | Not increased |
| Woman, 36" waist, 40" hips | 0.90 | Substantially increased risk |
What does waist-to-hip ratio tell you that BMI doesn't?
BMI is weight divided by height squared. It says nothing about where the weight is. Two people with the same BMI can store fat very differently — one mostly on the hips and thighs, the other mostly around the abdomen.
Abdominal fat, and particularly the visceral fat packed around the internal organs, is the type most closely tied to insulin resistance, type 2 diabetes and cardiovascular disease. Waist-to-hip ratio is a simple way to capture that central pattern with a tape measure.
In the INTERHEART study of around 27,000 people across 52 countries, waist-to-hip ratio was more strongly associated with heart attack than BMI was, and the authors suggested it as a better marker of obesity for that purpose.
What is a healthy waist-to-hip ratio?
| Sex | Not increased | Substantially increased risk of metabolic complications |
|---|---|---|
| Men | Below 0.90 | 0.90 and above |
| Women | Below 0.85 | 0.85 and above |
The WHO 2008 expert consultation also gives cut-offs for waist circumference alone. For men, a waist above 94 cm (about 37 in) marks increased risk and above 102 cm (about 40 in) substantially increased risk. For women the figures are 80 cm (about 31.5 in) and 88 cm (about 34.5 in). This calculator checks your waist against those as well.
How do you measure waist and hips for waist-to-hip ratio?
- 1.Stand upright with feet close together and arms relaxed at your sides, wearing light clothing or none over the area.
- 2.Waist: find the lower edge of your last rib you can feel and the top of your hip bone (iliac crest). Measure around the midpoint between them.
- 3.Read the waist measurement at the end of a normal breath out — don't hold your breath or pull your stomach in.
- 4.Hips: measure around the widest part of your buttocks.
- 5.Keep the tape parallel to the floor and snug, without compressing the skin. Measure each site twice and use the average if they differ.
This is the WHO protocol. Measuring the waist at the navel or at the narrowest point gives a different number, and the WHO cut-offs were set for the midpoint site.
Waist-to-hip ratio vs waist-to-height ratio vs waist alone
| Measure | What you need | Thresholds | Notes |
|---|---|---|---|
| Waist circumference | Waist only | Sex-specific (WHO: men > 94 / > 102 cm, women > 80 / > 88 cm) | Simplest; doesn't account for frame size |
| Waist-to-hip ratio | Waist and hips | Sex-specific (WHO: men 0.90, women 0.85) | Captures shape; hip size affects the ratio |
| Waist-to-height ratio | Waist and height | One threshold, 0.5, for both sexes | Scales the waist to body size |
Waist-to-hip ratio has one quirk the others don't: because the hips are in the denominator, the ratio can stay level if both waist and hips grow, or rise if the hips shrink. That is why the waist on its own is worth reading alongside it — this calculator shows both.
A 2012 systematic review and meta-analysis found waist-to-height ratio performed better than waist circumference and BMI for screening adult cardiometabolic risk factors. None of these measures is a diagnosis; each is a prompt for proper testing.
Who shouldn't rely on waist-to-hip ratio?
- Children and adolescents — the WHO adult cut-offs do not apply.
- Pregnancy — abdominal measurements reflect the pregnancy, not fat distribution.
- People of different ethnic backgrounds — the WHO report notes that the relationship between these measurements and risk varies between populations, so a single cut-off may not fit everyone equally.
Can you lower your waist-to-hip ratio?
Yes. Abdominal fat responds to an overall calorie deficit and to regular physical activity; spot exercises such as sit-ups do not selectively remove it. Because visceral fat is often lost relatively early in weight loss, the waist frequently shrinks before the scale moves much.
Remeasure every few weeks rather than daily. Meals, salt intake and hydration can change a waist measurement from one day to the next by enough to hide the real trend.
Frequently asked questions
What is a good waist-to-hip ratio?
By the WHO classification, below 0.90 for men and below 0.85 for women. At or above those cut-offs the WHO describes a substantially increased risk of metabolic complications. WHO does not grade the ratio further, so there is no official 'low' or 'moderate' band below the cut-off.
How do I calculate my waist-to-hip ratio?
Measure your waist midway between your lowest rib and the top of your hip bone, then your hips at the widest part of the buttocks, using the same units. Divide waist by hips. A 34-inch waist and 40-inch hips give a ratio of 0.85.
Is waist-to-hip ratio better than BMI?
It measures something BMI doesn't: where fat is stored. In the large INTERHEART study it was more strongly linked to heart attack than BMI. It isn't a replacement — using both, or adding waist-to-height ratio, gives a fuller picture than any single number.
Why are the cut-offs different for men and women?
Women typically carry more fat on the hips and thighs, which naturally lowers the ratio. The same ratio therefore reflects relatively more central fat in a woman than in a man, so the WHO threshold for women is lower: 0.85 compared with 0.90.
Where is the waist measured for this ratio?
At the midpoint between the lower edge of the last rib you can feel and the top of the hip bone, with the tape level and read at the end of a normal breath out. That is the WHO protocol; measuring at the navel gives a different result.
Does waist-to-hip ratio apply to children or during pregnancy?
No. The WHO cut-offs were set for adults and do not apply to children or adolescents. During pregnancy, waist measurements reflect the growing uterus rather than fat distribution, so the ratio carries no useful information about metabolic risk.
Sources
- Waist circumference and waist-hip ratio: report of a WHO expert consultation, Geneva, 8–11 December 2008 — World Health Organization, 2011
- Obesity and the risk of myocardial infarction in 27,000 participants from 52 countries: a case-control study — Yusuf et al., The Lancet, 2005
- Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors: systematic review and meta-analysis — Ashwell et al., Obesity Reviews, 2012