Waist-to-hip is waist divided by hips, and the useful thing to understand is that the bottom of that fraction moves it as much as the top does. Two people with an identical 95cm waist land on opposite sides of the WHO threshold depending only on how wide their hips are — hips of 105cm give 0.90 and...
A screening figure, not a diagnosis — and a weaker one than it looks. The published thresholds catch a surprisingly small share of the people they are meant to identify: a 100cm waist in men flags only about 8.5% of those with two or more cardiometabolic risk factors. Sitting under a cut-off is therefore not reassurance, and sitting over one is not a verdict. What either is worth is mentioning at your next appointment, where it can sit alongside blood pressure, glucose and the rest of a picture no tape measure can see.
WHICH CUT-OFFS
Measure at the right places, and the same places each time. The WHO protocol puts the waist at the midpoint between the lowest rib and the top of the hip bone, and the hips at the widest point over the buttocks, at the end of a normal breath out. Some studies measure the waist at the navel instead, which reads several centimetres differently on the same person — and the published cut-offs belong to a protocol. A couple of centimetres either way moves the ratio by more than the precision anyone quotes it to.
WAIST TO HIP RATIO
0.90
95.0cm divided by 105.0cm, against a threshold of 0.90 for men on the WHO general cut-offs. That is at or above the threshold.
RATIO
0.90
THRESHOLD
0.90
WAIST
95cm
A ratio can be moved by its denominator, and this one is. With the same 95cm waist, hips of 106cm would put you exactly on the threshold — 1cm wider than your measurement. Nothing about the abdomen changes along that line. And the fat that widens hips is gluteofemoral, which behaves differently from the visceral fat this measure is trying to find — so a low ratio from wide hips is not the same finding as a low ratio from a narrow waist, though the number cannot tell them apart.
The cut-offs are not the same for everyone. The general figures come largely from European populations. For people of South Asian, Chinese or Japanese descent the waist thresholds are lower — 90cm for men rather than 94 or 102 — because the same waist carries more visceral fat and more metabolic risk at a smaller measurement. The Asian Indian consensus of 2009 uses those lower figures. If that applies to you, switch the cut-offs above; it can change the answer without changing anything about you.
Waist to hip
0.905
WHR threshold
0.90
Waist
95.0 cm
Raised risk from
94.0 cm
Substantial from
102.0 cm
Waist to height
0.534
What a tape measure cannot see. It knows nothing about blood pressure, blood sugar, cholesterol, fitness, sleep or family history, and those are what the measurement is standing in for. It also cannot distinguish visceral fat from muscle or from a large frame. Pregnancy, bloating and where in the day you measure all move it. Published sources disagree on the thresholds themselves — the WHO puts the men's ratio at 0.90 while the USDA uses 0.95 — which is a reasonable signal that the boundary is softer than a single number suggests.
THE RATIO
Every point on this line is the same abdomen. The ratio falls as the hips widen, which is the measure working as designed — wider hips genuinely do carry a different risk profile. But it means a reassuring ratio can come from either end of the fraction, and the number alone will not tell you which.
WHO and IDF thresholds · live calculation
Measure the waist at the midpoint between your lowest rib and the top of your hip bone, at the end of a normal breath out. Some studies use the navel instead, which reads several centimetres differently on the same person — and the published cut-offs belong to a protocol.
Measure the hips at the widest point over the buttocks, with the tape level and snug but not compressing. Take each measurement twice and use the average; a couple of centimetres moves the ratio by more than the precision anyone quotes it to.
Choose the cut-off set that applies to you. The general figures come from European populations; the lower ones are for people of South Asian, Chinese or Japanese descent, where the same waist carries more risk.
Add your height to see waist-to-height as well. It needs no separate threshold by sex — keep your waist under half your height — and it frequently disagrees with the ratio, which tells you something the ratio alone does not.
Last updated: August 1, 2026 · WHO 2008 expert consultation and IDF ethnicity-specific cut-offs · Sensitivity figures from the AHA review · A screening estimate, not medical advice.