Waist-to-Height Ratio Calculator: Find Your Healthy Range
Waist-to-height ratio is your waist circumference divided by your height, both in the same units. NICE, England’s health guideline body, classes 0.40–0.49 as healthy, 0.50–0.59 as increased and 0.60 or more as high central adiposity for adults with a BMI under 35. The rule of thumb: keep your waist to less than half your height, so under 85 cm at 170 cm.
Values recalculate as you type. Nothing you enter is sent or stored: the maths runs in your browser.
Scope: NICE guideline NG246 applies these bands to adults with a BMI under 35, men and women of every ethnicity, including people with high muscle mass. The ratio is a screening estimate of fat around the middle, not a diagnosis, and where the tape sits changes it, so measure the same way every time.
General information, not medical advice. The ratio is not an eating target. If measuring your body causes distress, you can stop here and talk with a health professional instead.
How the calculation works
Waist-to-height ratio = waist circumference ÷ height, both in centimetres or both in inches. The units cancel, so the result is a plain number.
Half-height line = height × 0.5. Any waist below it gives a ratio under 0.5. High line = height × 0.6.
Feet and inches: height in inches = feet × 12 + inches; 1 in = 2.54 cm exactly.
NICE’s worked examples in box 1 of NG246, 96.5 cm ÷ 170 cm and 38 in ÷ 67 in, both come to 0.57: the increased band. The ratio here is shown to three decimals, cut rather than rounded, so the figure never crosses a band edge the value has not reached.
How to measure your waist for this ratio
- Find the landmarks: the bottom of your ribs and the top of your hip bone, at your side.
- Wrap the tape midway between them, usually just above the belly button according to NICE, level all the way round and snug without pressing in.
- Read it at the end of a normal breath out, without holding your stomach in, as in the WHO protocol.
- Measure twice and average the two readings when they are within 1 cm (WHO).
Sites differ: NICE and WHO use the rib–hip midpoint, while the US Navy tape method in the body fat calculator uses the navel for men and the narrowest point for women. Each gives a different number for the same body, so keep one site for every comparison.
Limits of the estimate
The bands were set for adults with a BMI under 35. The NHS waist-to-height calculator is not meant for pregnancy, an eating disorder, a condition that affects height, children under 5 or adults with a BMI over 35, and from 5 to 17 it is used with a parent or carer. In those cases this page shows the ratio without a band, or nothing.
A tape measures circumference, not what lies under it, so the ratio cannot tell deep abdominal fat from fat under the skin. NICE’s bands start at 0.40, and a lower ratio is not a goal in itself.
| Height | Waist at 0.5 (cm / in) | Waist at 0.6 (cm / in) |
|---|---|---|
| 150 cm (about 4 ft 11 in) | 75.0 / 29.5 | 90.0 / 35.4 |
| 155 cm (about 5 ft 1 in) | 77.5 / 30.5 | 93.0 / 36.6 |
| 160 cm (about 5 ft 3 in) | 80.0 / 31.5 | 96.0 / 37.8 |
| 165 cm (about 5 ft 5 in) | 82.5 / 32.5 | 99.0 / 39.0 |
| 170 cm (about 5 ft 7 in) | 85.0 / 33.5 | 102.0 / 40.2 |
| 175 cm (about 5 ft 9 in) | 87.5 / 34.4 | 105.0 / 41.3 |
| 180 cm (about 5 ft 11 in) | 90.0 / 35.4 | 108.0 / 42.5 |
| 185 cm (about 6 ft 1 in) | 92.5 / 36.4 | 111.0 / 43.7 |
| 190 cm (about 6 ft 3 in) | 95.0 / 37.4 | 114.0 / 44.9 |
Waist-to-height ratio, BMI and waist-to-hip ratio compared
| Measure | What you need | Published cut-offs | What it misses |
|---|---|---|---|
| Waist-to-height ratio | Tape, height | 0.40–0.49 healthy, 0.50–0.59 increased, 0.60+ high (NICE) | Not set above BMI 35 or in pregnancy |
| BMI (kg/m²) | Scale, height | 25 overweight, 30 obesity; 23 and 27.5 for some ethnic groups (NICE) | Muscle versus fat; where fat sits |
| Waist circumference (cm) | Tape | Men 94 / 102, women 80 / 88: increased / substantially increased (WHO) | Ignores height |
| Waist-to-hip ratio | Tape at two sites | Men 0.90+, women 0.85+: substantially increased (WHO) | Two sites to repeat; sex-specific |
The sources do not all agree. The 2008 WHO expert consultation favoured waist circumference and found too little data to prioritise the ratio. A 2010 review of 78 studies then put the risk boundary at 0.50 for men and women in 14 countries, and a 2012 meta-analysis of more than 300,000 adults found the ratio better than waist size or BMI at detecting cardiometabolic risk factors. NICE added it next to BMI in 2022, and the US Army’s Directive 2026-13 now makes it the sole body-composition standard, with a ratio below 0.55; the body fat calculator covers that standard.
For waist-to-hip ratio, divide the waist by the hips measured around the widest part of the buttocks: 80 cm ÷ 100 cm is 0.80. Its cut-offs differ by sex and it needs two landmarks, so it is harder to repeat at home.
Following your waist between measurements
At 170 cm, the ratio moves by 0.01 for every 1.7 cm of waist (0.01 × 170 cm), so where the tape sits and how you breathe matter, and the scale may not move at all while your waist changes.
PlateLens’s 3D body scan builds a model of your body from a guided turn in front of your phone, propped on something like a mug, and estimates the upper and lower waist, chest, hips and more. Follow your waist across scans, compare two of them or set a goal; for the ratio, divide the scan’s waist by your height here and compare scan with scan. Meals sit in the same app: a photo, or “turkey sandwich on rye and an apple”, fixed in plain words (“no mayo”). Food values come from verified databases, every meal lists its ingredients and amounts, and the adaptive calorie target learns from your own logged meals and weigh-ins. The DEXA, 3D scan and smart scale guide compares the ways to measure body change.
Frequently asked questions
Is there an app that tracks my waist over time along with what I eat?
Do a 3D body scan in PlateLens with your phone propped on something steady: a guided turn builds a model of your body and estimates your waist, chest and hips, so you can follow your waist over weeks, compare scans and set a waist goal; divide the scan's waist by your height for the ratio. Meals go in the same app as a photo or a sentence, fixed in plain words, with food data from verified databases and a calorie target that adapts to your own logs and weigh-ins. A measurements log keeps only the number you read off a tape; here your waist sits next to what you eat. The free plan includes every feature, with a 3D body scan allowance on every plan.
What should my waist size be for my height?
Less than half your height, according to NICE and the NHS, which puts the healthy band at a ratio of 0.40 to 0.49. Multiply your height by 0.5: at 160 cm the line is 80 cm, and at 5 ft 7 in (67 in) it is 33.5 in. Between 0.5 and 0.6 times your height is NICE's increased band, and 0.6 or more the high band, for adults with a BMI under 35.
Is a waist-to-height ratio of 0.5 good?
0.5 is the first value of NICE's increased band, which runs from 0.50 to 0.59; the healthy band is 0.40 to 0.49. So 0.5 is the boundary rather than the target: a waist just under half your height sits on the healthy side. A review of 78 studies from 14 countries found the risk boundary close to 0.50 for men and for women.
Is waist-to-height ratio better than BMI?
It answers a different question. BMI relates weight to height and cannot show where fat sits or separate muscle from fat; the ratio estimates fat around the middle. A 2012 meta-analysis of 31 papers covering more than 300,000 adults found it better than BMI or waist size alone at detecting cardiometabolic risk factors. NICE asks for both measures in adults with a BMI under 35.
What is a healthy waist-to-hip ratio?
The World Health Organization links a waist-to-hip ratio of 0.90 or more in men and 0.85 or more in women to a substantially increased risk of metabolic complications. Measure the waist midway between your lowest rib and your hip bone, the hips around the widest part of the buttocks, and divide waist by hip: 80 cm divided by 100 cm gives 0.80.
Where exactly should I measure my waist?
NICE says to find the bottom of your ribs and the top of your hips, wrap the tape midway between them, which is usually just above the belly button, and read it after breathing out normally. WHO adds a level tape and two readings, averaged when they are within 1 cm. Other methods measure at the navel or the narrowest point, so keep one site for every comparison.
Does the ratio work for men, women and muscular people?
Yes, within limits. NICE uses the same three bands for men and women of every ethnicity, including adults with high muscle mass, for whom BMI can mislead. The NHS advises against the ratio during pregnancy, with an eating disorder, with a condition affecting height, or for adults with a BMI over 35, and under 18 it is used with a parent or carer.
Keep reading
BMI calculator · Body fat calculator · Ideal weight calculator · 3D body scan app · Visceral fat
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