Waist-to-hip ratio and waist-to-height ratio from tape measurements, with the WHO risk cut-offs, the NICE bands and the WHO waist size category.
By AdminDrafted with AI writing toolsUpdated Checked examples: 5
Your waist-to-hip ratio is 0.86 (not increased risk by the WHO cut-off of 0.90) and your waist is 49 % of your height (healthy by NICE's bands).
Categories are read from the ratio rounded to 2 decimals, as displayed.
NICE bands: 0.4–0.49 healthy, 0.5–0.59 increased, 0.6 or more high.
86 cm against the WHO cut-offs of 94 cm (increased) and 102 cm (substantially increased) for men.
Waist-to-hip ratio (WHR) is waist circumference divided by hip circumference, and waist-to-height ratio (WHtR) is waist divided by height in the same unit. Both measure fat carried around the middle, which BMI misses. WHR is compared with the WHO 2008 cut-offs of 0.90 for men and 0.85 for women, and waist size alone with the WHO thresholds of 94 and 102 cm for men and 80 and 88 cm for women.
People use these ratios to screen for central obesity, which is linked to type 2 diabetes and cardiovascular disease. With the defaults, a man with an 86 cm waist, 100 cm hips and a height of 175 cm has a WHR of 0.86, below the WHO cut-off, and a WHtR of 0.49, inside NICE's healthy band of 0.4 to 0.49.
The cut-offs are population thresholds, mostly set in Europid adults, not diagnoses. They assume the WHO method: waist midway between the lowest rib and the top of the hip bone after a normal breath out.
Divide your waist circumference by your hip circumference, both in the same unit. An 86 cm waist and 100 cm hips give 86 ÷ 100 = 0.86. A 2008 WHO expert consultation placed substantially increased risk of metabolic complications at 0.90 or more for men and 0.85 or more for women.
The hip measurement counts too: the same 86 cm waist with 94 cm hips gives 0.91, over the men's line.
These cutoffs are population screening thresholds for adults, mostly set in Europid populations. A result near the line says little about one person on its own and is not a diagnosis.
Divide your waist by your height in the same unit. An 86 cm waist at 175 cm tall gives 86 ÷ 175 = 0.49.
NICE grades the result in three bands for adults:
The public-health rule of thumb is to keep your waist under half your height. At 175 cm, that means a waist below 87.5 cm.
A 2012 meta-analysis by Ashwell and colleagues found waist-to-height ratio a better screen for cardiometabolic risk than waist circumference or BMI. NICE guidance describes its use in adults with a BMI below 35.
WHO also grades waist circumference on its own:
These thresholds start above the number, so a man with a waist of exactly 102 cm stays in the increased band.
The WHO waist cutoffs come mainly from Europid adults. The International Diabetes Federation uses lower thresholds for South Asian and Chinese adults: 90 cm for men and 80 cm for women.
The female example is a 70 cm waist, 98 cm hips and 165 cm height. The imperial example is a 40-inch waist, 38-inch hips and a height of 6 ft.
| Scenario | Waist-to-hip ratio | Waist-to-height ratio |
|---|---|---|
| Default | 0.86 | 0.49 |
| Female example | 0.71 | 0.42 |
| Imperial example | 1.05 | 0.56 |
The default is the man from the first section. The woman sits under the women's 0.85 line and inside NICE's healthy band.
The imperial example shows why the three checks are read separately. His ratio of 1.05 is well over the men's 0.90 line, but his 40-inch waist is 101.6 cm, in the increased band and not yet above 102 cm.
The published cutoffs assume the method in the WHO expert-consultation report:
Measuring at the navel gives a different number from the WHO site. With 100 cm hips, a 2 cm error at the waist moves the ratio by 0.02, enough to cross a cutoff when you are close to one.
For weight relative to height, use the BMI calculator. To estimate how much of your weight is fat, use the body fat calculator.
Checked against: 90/100 = 0.90 meets the WHO ≥ 0.90 cut-off; 90/175 = 0.5143 is in NICE's 0.5–0.59 band; 90 cm ≤ 94 cm
Checked against: 70/98 = 0.7143 < 0.85; 70/165 = 0.4242 in NICE 0.4–0.49
Checked against: 40/38 = 1.0526; 40/72 = 0.5556; 101.6 cm is above 94 cm but not above 102 cm (WHO)
Checked against: Hand calculation: 85/170 = 0.5, the start of NICE's 0.5–0.59 increased-risk band
Below 0.90 for men and below 0.85 for women, the cut-offs at which a 2008 WHO expert consultation placed substantially increased risk of metabolic complications. A man with an 86 cm waist and 100 cm hips has 0.86, under the line; the same waist with 94 cm hips gives 0.91, over it. These are population thresholds, so a ratio near the line says little about one person on its own.
WHO links a waist above 94 cm (37 in) in men and 80 cm (31.5 in) in women to increased risk of metabolic complications, and above 102 cm (40 in) and 88 cm (34.6 in) to substantially increased risk. These cut-offs come mainly from Europid populations. The International Diabetes Federation uses lower thresholds for South Asian and Chinese adults: 90 cm for men and 80 cm for women.
Under 0.5, the basis of the public-health message to keep your waist to less than half your height. NICE's bands, added to its obesity guidance in 2022, are 0.4 to 0.49 healthy, 0.5 to 0.59 increased and 0.6 or more high central adiposity. A 2012 meta-analysis by Ashwell and colleagues found WHtR a better screen for cardiometabolic risk than waist circumference or BMI.
WHO measures the waist midway between the lowest rib and the top of the hip bone at the end of a normal breath out, and the hips around the widest part of the buttocks, with the tape level and snug but not compressing the skin. The published cut-offs assume this method. Measuring at the navel gives a different number, and a 2 cm change in waist moves the ratio by 0.02 when hips are 100 cm.
For information only, not medical advice. These formulas describe populations, not you; talk to a clinician before acting on a result.
This calculator includes 5 worked examples with independently sourced answers. They run in the test suite, and you can run them here too.