Waist to Hip Ratio Calculator

Your waist-to-hip ratio is a proportion, not a size. It tells you how your waist compares with your hips — and nothing at all about either measurement on its own. Two women can share the same ratio with waists twenty centimetres apart, and a calculator that reports only the ratio gives them both the same answer.

That is why this page does not stop at the ratio. It gives you the ratio, the category it falls into, styling advice for that proportion — and a note when your waist itself reaches the line health guidance uses, because the waist measurement is the one the evidence is strongest about.

The thresholds, and who set them

The waist-to-hip figures come from the WHO Expert Consultation on Waist Circumference and Waist–Hip Ratio. At or above these numbers, the WHO classes it as abdominal obesity — a screening category, not a diagnosis. A screening category sorts people for a closer look; it does not diagnose anyone.

One honest note about this calculator: it does not ask whether you are a woman or a man, so its bands are drawn around the women’s WHO line of 0.85. If you are a man, your line is 0.90 — use the table above, not the label in the result.

Another: the WHO waist figures come from populations of primarily European descent. For South Asian, Chinese and Japanese populations the equivalent waist cut-offs are lower, and applying the European numbers will under-flag risk.

Why a good ratio can hide a large waist

The ratio is waist divided by hips. Turn that round and you get waist = ratio × hips — so the larger your hips, the more waist you can carry before the ratio says anything at all.

Identical ratios, twenty centimetres of waist between them. Two exact crossover points fall out of this, for women: with hips above 103.5 cm, a passing ratio permits a waist beyond 88 cm — the WHO substantially-increased-risk line. With hips below 94.1 cm, the ratio flags you while your waist is still under 80 cm, which the WHO treats as unremarkable.

How often does this matter? Across 14,144 plausible waist and hip combinations for women, about 21% produced a passing ratio while the waist sat in the substantially-increased-risk band, and 2.4% were flagged by the ratio while the waist was entirely healthy. For men the figures were 16.4% and 4.6%. One in five wrongly reassured is not a rounding error — which is why this calculator adds a note when your waist itself reaches 35 inches (about 88 cm), instead of leaving you with the ratio alone.

The popular calculators disagree about men

Worth knowing if you have looked this up before and got a different answer. Among the highest-ranking waist-to-hip calculators, one puts men’s “low risk” at 0.95 or below, while the WHO — and other calculators quoting the WHO — put abdominal obesity at 0.90 or above.

So a man with a ratio of 0.92 is told he is at low risk by one page and that he meets the definition of abdominal obesity by another. More awkwardly, the calculator using 0.95 quotes the WHO 0.90 figure in its own body text on the same page — its table and its prose contradict each other.

We use the WHO’s numbers throughout, for both sexes, and the top band begins exactly where the WHO says it does: 0.85 for women, 0.90 for men.

How to measure properly

Most of the error in this calculation comes from the tape, not the arithmetic. Two minutes and a soft tape, done properly, beat any amount of precision in the formula.

One thing that trips up comparisons: different bodies of guidance use different waist landmarks. The WHO uses the rib-to-hip midpoint; some large American surveys measure at the top of the hip bone instead. On the same person those can differ by several centimetres. If you are comparing today’s number against one from years ago, make sure both were taken in the same place.

Apple, pear, and what the shape actually means

A lower ratio is the pattern usually called pear-shaped: weight carried at the hips and thighs. A higher ratio is apple-shaped: weight around the middle.

The reasoning behind the measure is that where fat sits seems to matter independently of how much of it there is. Fat stored around the organs is more metabolically active than fat stored at the hips and thighs, which is why two people at the same weight can sit differently on a risk chart.

Two honest caveats. First, muscle counts as hips — someone with well-developed glutes has a lower ratio for reasons unconnected to abdominal fat, and the tape cannot tell the difference. Second, this is not the same question as the one our body shape calculator answers. That one sorts you into seven shapes for the purpose of buying clothes that fit. This one is about fat distribution and health screening. Related, but not interchangeable.

What changes after 40

This is where the ratio becomes genuinely misleading, and it is the part most calculators say nothing about.

Your ratio can rise without your waist changing at all

The hips are the denominator. Anything that makes them smaller pushes the ratio up — and glute and thigh muscle is lost steadily from midlife onward.

Menopause moves fat waist-ward at the same weight

Separately from any weight change, fat redistributes from the hips toward the waist after menopause. Shift three centimetres from hips to waist at identical body weight and the ratio moves by about 0.056 — most of the way across a category, with the scales reading exactly the same.

Both effects push in the same direction, and neither is what the ratio is trying to detect. This is why the waist measurement itself is the more stable thing to track after 40, and waist-to-height more stable still: losing three centimetres of height moves waist-to-height by less than 0.01.

There is a practical upshot. Resistance training that maintains glute and thigh muscle keeps the denominator up — which is a genuine reason to lift something heavy twice a week, and a considerably better one than the number on this page.

Where this measurement falls down

• It is not a diagnosis and cannot be. It knows nothing about your blood pressure, your blood sugar, your fitness, your family history or how you feel.
• Thresholds are lines drawn through continuous data. Nothing happens to you at 0.85 that did not happen at 0.84.
• It was built to sort populations, not to judge individuals. That is a real distinction and it gets lost constantly.
• Bloating, digestive conditions, some medications and abdominal surgery all move a waist measurement without moving anything about long-term risk.
• If numbers like these are unhelpful for you — and for some people they genuinely are — that is a perfectly good reason to close the tab. The measurement is not going anywhere.

Frequently asked questions