Waist to Height Ratio Calculator
Your WHtR, the 0.5 boundary and the waist size that fits your height
A waist to height ratio calculator divides your waist circumference by your height, both in the same unit. Under NICE guidance, a ratio from 0.40 to 0.49 (a waist less than half your height) is the healthy range, 0.50 to 0.59 signals increased health risk and 0.60 or more high risk. A 5 ft 10 in man with a 36 inch waist has a ratio of 0.51, one inch above the 35 inch waist that would be exactly half his height.
Last updated October 2026
Method: Waist-to-height ratio = waist ÷ height, both in inches or both in centimeters. Bands from NICE guideline NG246 (January 2025, updated January 2026): 0.40 to 0.49 healthy, 0.50 to 0.59 increased and 0.60 or more high central adiposity, with values under 0.40 shown separately. The exact ratio is compared with each boundary, so a waist a fraction under half your height counts as below 0.5. The optional BMI uses the CDC adult categories.
Included: US and metric units, your ratio and band, the waist sizes at 0.4, 0.5 and 0.6 for your height, how far you are from half your height, a scale graphic, the NIH waist-size check and an optional BMI comparison.
Not included: Pregnancy, children under 5, body fat percentage and waist-to-hip ratio (see the linked calculators). For a BMI of 35 or more, NICE relies on BMI rather than these bands. This is a screening estimate, not a diagnosis.
📏 Your measurements
📏 Your waist-to-height ratio
Ratio = waist ÷ height = 36.0 ÷ 70.0 in. The healthy band ends just below half your height.
🎯 Where you sit on the scale
Your ratio of 0.51 falls in the band 0.50 to 0.59.
Increased central adiposity
Your waist is at least half your height. NICE links 0.50 to 0.59 with increased health risks such as type 2 diabetes, high blood pressure and cardiovascular disease.
📋 Bands translated to your height (5 ft 10 in)
| Band | Ratio | Waist for you |
|---|---|---|
| Below 0.40 | under 0.40 | under 28.0 in |
| Healthy central adiposity | 0.40 to 0.49 | 28.0 in to under 35.0 in |
| Increased central adiposity | 0.50 to 0.59 | 35.0 in to under 42.0 in |
| High central adiposity | 0.60 or more | 42.0 in or more |
Bands from NICE guideline NG246 for adults with a BMI under 35 and children aged 5 and over, the same for both sexes and all ethnic groups.
⚖️ Cross-checks
Waist to height ratio calculator: the half-your-height rule explained
The waist-to-height ratio, often shortened to WHtR, measures how much of your size sits around your middle. Fat carried around the middle, called central adiposity, is linked with type 2 diabetes, high blood pressure and cardiovascular disease, as NICE notes, and the waist is the easiest place to measure it. Dividing the waist by your height turns that measurement into a number that means the same for a short woman and a tall man.
The ratio became popular because its message fits in one sentence: keep your waist to less than half your height. NICE, the body that writes clinical guidelines for England, added it to its obesity guideline in 2022 and kept it in the 2025 update for adults with a BMI under 35 and for children from age 5.
How the waist-to-height ratio is calculated
WHtR = waist circumference ÷ height Waist at the 0.5 boundary = height × 0.5 Change needed = waist − height × 0.5 Both measurements must be in the same unit. Convert feet to inches first (5 ft 10 in is 70 inches) or use centimeters for both. Because the units cancel, the ratio is the same in either system: a 36 inch waist at 70 inches and a 91.44 cm waist at 177.8 cm both give 0.514.
Worked example: 5 ft 10 in with a 36 inch waist
A man who is 5 ft 10 in tall (70 inches) measures his waist at 36 inches. His ratio is 36 ÷ 70 = 0.514, which the calculator shows as 0.51. That places him in the increased central adiposity band, 0.50 to 0.59.
Half his height is 35.0 inches, so he is 1.0 inch over the boundary. His healthy band runs from 28.0 inches (0.40) to just under 35.0 inches, and the high band starts at 42.0 inches (0.60). At 185 lb his BMI is 26.5, in the overweight range. To reach a ratio of 0.49 he would need a waist of 0.49 × 70 = 34.3 inches, 1.7 inches less than today. This is the calculator's default input.
Worked example in metric: a healthy BMI with a high ratio
NICE's own guideline uses this pair of numbers as its example: a waist of 96.5 cm and a height of 170 cm. The ratio is 96.5 ÷ 170 = 0.568, shown as 0.57, in the increased band. Half her height is 85.0 cm, so the waist is 11.5 cm over the boundary.
Now add a weight of 72 kg. Her BMI is 72 ÷ 1.7² = 24.9, inside the CDC's healthy weight range of 18.5 to under 25. Judged by BMI alone she would hear that everything is fine. The waist-to-height ratio tells a different story: a good share of her weight sits around her middle. This is the pattern the ratio is best at catching, and a UK survey analysis of 1,453 adults by Ashwell and Gibson found that 35% of those rated at no increased risk by BMI and waist size together had a ratio of 0.5 or more.
The healthy range and the risk bands
NICE guideline NG246 classifies central adiposity with three bands that apply to both sexes and all ethnic groups:
- 0.40 to 0.49, healthy central adiposity: no increased health risk.
- 0.50 to 0.59, increased central adiposity: increased health risk.
- 0.60 or more, high central adiposity: further increased health risk.
The guideline names type 2 diabetes, high blood pressure and cardiovascular disease as the main risks. It does not define a band below 0.40. A ratio that low usually reflects a slim frame, but if your BMI is also under 18.5, the CDC's underweight cutoff, it is worth a conversation with a clinician. Take a woman who is 5 ft 4 in (64 inches) with a 30 inch waist: her ratio is 30 ÷ 64 = 0.469, in the healthy band, with 2.0 inches of room before she reaches half her height at 32.0 inches. At 140 lb her BMI is 24.0.
Waist size at ratio 0.5 for every height
This table turns the bands into waist sizes. Find your height, and the bold column is the waist at which you reach exactly half your height. Below that number you are in the healthy band; from it up to the 0.6 column you are in the increased band. All values are computed directly from height × ratio.
| Height | Height (cm) | Waist at 0.4 (in) | Waist at 0.5 (in) | Waist at 0.5 (cm) | Waist at 0.6 (in) |
|---|---|---|---|---|---|
| 4 ft 10 in | 147.3 | 23.2 | 29.0 | 73.7 | 34.8 |
| 4 ft 11 in | 149.9 | 23.6 | 29.5 | 74.9 | 35.4 |
| 5 ft 0 in | 152.4 | 24.0 | 30.0 | 76.2 | 36.0 |
| 5 ft 1 in | 154.9 | 24.4 | 30.5 | 77.5 | 36.6 |
| 5 ft 2 in | 157.5 | 24.8 | 31.0 | 78.7 | 37.2 |
| 5 ft 3 in | 160.0 | 25.2 | 31.5 | 80.0 | 37.8 |
| 5 ft 4 in | 162.6 | 25.6 | 32.0 | 81.3 | 38.4 |
| 5 ft 5 in | 165.1 | 26.0 | 32.5 | 82.5 | 39.0 |
| 5 ft 6 in | 167.6 | 26.4 | 33.0 | 83.8 | 39.6 |
| 5 ft 7 in | 170.2 | 26.8 | 33.5 | 85.1 | 40.2 |
| 5 ft 8 in | 172.7 | 27.2 | 34.0 | 86.4 | 40.8 |
| 5 ft 9 in | 175.3 | 27.6 | 34.5 | 87.6 | 41.4 |
| 5 ft 10 in | 177.8 | 28.0 | 35.0 | 88.9 | 42.0 |
| 5 ft 11 in | 180.3 | 28.4 | 35.5 | 90.2 | 42.6 |
| 6 ft 0 in | 182.9 | 28.8 | 36.0 | 91.4 | 43.2 |
| 6 ft 1 in | 185.4 | 29.2 | 36.5 | 92.7 | 43.8 |
| 6 ft 2 in | 188.0 | 29.6 | 37.0 | 94.0 | 44.4 |
| 6 ft 3 in | 190.5 | 30.0 | 37.5 | 95.3 | 45.0 |
| 6 ft 4 in | 193.0 | 30.4 | 38.0 | 96.5 | 45.6 |
| 6 ft 5 in | 195.6 | 30.8 | 38.5 | 97.8 | 46.2 |
| 6 ft 6 in | 198.1 | 31.2 | 39.0 | 99.1 | 46.8 |
Each extra inch of height raises the 0.5 waist by half an inch. That is why a fixed waist cutoff cannot be fair to everyone: the gap between the 0.5 waist of a 4 ft 10 in woman (29.0 inches) and a 6 ft 6 in man (39.0 inches) is a full 10 inches.
Ratio chart for common waist and height combinations
Read across from your waist size to the column nearest your height. Values below 0.40 are blue, the healthy band green, the increased band amber and 0.60 or more red.
| Waist | 5 ft 0 in | 5 ft 4 in | 5 ft 8 in | 6 ft 0 in | 6 ft 4 in |
|---|---|---|---|---|---|
| 26 in | 0.43 | 0.41 | 0.38 | 0.36 | 0.34 |
| 28 in | 0.47 | 0.44 | 0.41 | 0.39 | 0.37 |
| 30 in | 0.50 | 0.47 | 0.44 | 0.42 | 0.39 |
| 32 in | 0.53 | 0.50 | 0.47 | 0.44 | 0.42 |
| 34 in | 0.57 | 0.53 | 0.50 | 0.47 | 0.45 |
| 36 in | 0.60 | 0.56 | 0.53 | 0.50 | 0.47 |
| 38 in | 0.63 | 0.59 | 0.56 | 0.53 | 0.50 |
| 40 in | 0.67 | 0.63 | 0.59 | 0.56 | 0.53 |
| 42 in | 0.70 | 0.66 | 0.62 | 0.58 | 0.55 |
| 44 in | 0.73 | 0.69 | 0.65 | 0.61 | 0.58 |
| 46 in | 0.77 | 0.72 | 0.68 | 0.64 | 0.61 |
A 36 inch waist is a good illustration: 0.60 at 5 ft 0 in, 0.53 at 5 ft 8 in and 0.47 at 6 ft 4 in. The same tape measure reading means three different things.
Why researchers favor the ratio
The case for the waist-to-height ratio rests on large reviews. In 2010, Browning, Hsieh and Ashwell pooled 78 studies and found average areas under the ROC curve (a measure of how well a test separates people with and without a condition) of 0.704 for the ratio, 0.693 for waist circumference and 0.671 for BMI. Across 14 countries, the average boundary value was 0.50 for men and 0.50 for women.
A 2012 meta-analysis by Ashwell, Gunn and Gibson then compared the measures within the same studies, covering more than 300,000 adults in several ethnic groups. Waist circumference improved on BMI by about 3%, and the ratio by 4% to 5%. The ratio was significantly better than waist circumference for diabetes, high blood pressure and cardiovascular disease in both men and women. A 2020 analysis of 4,112 adults in the Health Survey for England added a practical finding: among adults with raised long-term blood sugar, 15% looked like "no increased risk" on the BMI and waist matrix, but only 3% had a ratio under 0.5.
Waist-to-height ratio, BMI and waist-to-hip ratio compared
- BMI divides weight by height squared. It is simple and widely used, but it cannot tell muscle from fat or show where fat is stored.
- Waist circumference uses fixed cutoffs: NIH and CDC flag more than 40 inches for men and more than 35 inches for women. Those numbers ignore height.
- Waist-to-hip ratio divides the waist by the hips, with separate cutoffs for men and women, and moves if the hips change.
- Waist-to-height ratio divides the waist by height, uses one boundary for everyone and adjusts automatically for body size.
Height adjustment matters at both ends. A 6 ft 4 in man with a 38 inch waist is under the 40 inch cutoff, yet his ratio is exactly 0.50. A 5 ft 0 in woman with a 32 inch waist is under the 35 inch cutoff, yet her ratio is 0.53. The fixed cutoffs would clear both of them; the ratio places both in the increased band.
How to measure your waist
- Stand up straight, relaxed, with your feet together and your belly uncovered.
- Find the bottom of your ribs and the top of your hip bones. NICE places the tape midway between them, which is usually just above the belly button.
- Wrap the tape around your waist so it is level all the way around, snug but not pressing into the skin.
- Breathe out normally and read the tape at the end of the breath, without pulling your stomach in.
- Measure your height without shoes, standing against a wall, rather than using the number on an old license.
US agencies describe slightly different spots. NIH and CDC tell you to measure just above your hip bones after you breathe out, and the national NHANES survey marks the top of the right hip bone and reads the tape at the end of a normal breath out. The spots do not always give the same number, so pick one method and keep it. For tracking, measure at the same time of day, ideally in the morning, and look at the trend over weeks rather than single readings.
How to use this calculator
- Pick US units or metric. Enter height in feet and inches or in centimeters.
- Enter your waist in the same system, measured as described above.
- Add your weight if you like. It is optional and only used for the BMI comparison.
- Choose your sex for the NIH waist-size check. The ratio itself is the same for everyone.
- Read the result. The headline is your ratio and band. The tiles show half your height, how far you are from it and your healthy waist range. Below are a scale graphic, the bands translated into waist sizes for your height and the cross-checks.
Who this calculator is for
It is for adults who want a quick, height-fair check of belly fat, especially people whose BMI looks normal but whose waist has crept up, and people with a lot of muscle whose BMI overstates their risk. It is also useful for tracking progress during a fitness or weight-loss plan, since it responds directly to changes around the middle. Parents can use it for children from age 5, the age from which NICE applies the same bands, and coaches and students can use the tables to see how the boundary scales with height.
Limitations
The ratio is a screening measure. It estimates central fat from a tape measure and cannot see how much of your waist is fat around the organs and how much is just under the skin. NICE limits its bands to adults with a BMI under 35 because, as its committee put it, people above that BMI are always likely to have a high ratio, so the ratio adds little to the risk picture. The ratio does not apply during pregnancy, and a bloated stomach, a heavy meal or a tape placed a few inches higher can shift the result by a few hundredths. Finally, a ratio is not a diagnosis. A high value is a reason to check blood pressure, blood sugar and cholesterol with a clinician, not a verdict on your health.
Related calculators
- For weight relative to height, use the BMI Calculator.
- To compare your waist with your hips instead of your height, use the Waist-to-Hip Ratio Calculator.
- For an estimate of total body fat from tape measurements, use the Body Fat Calculator.
- High blood pressure is one of the risks the ratio flags. Check your readings with the Blood Pressure Calculator.
- To estimate blood alcohol and how long it takes to reach zero, use the BAC Calculator.
- To set a goal weight range, use the Ideal Weight Calculator.
Sources
- National Institute for Health and Care Excellence (NICE), Overweight and obesity management, guideline NG246, published January 2025 and updated January 2026 (recommendations 1.9.8, 1.9.14, 1.9.15 and 1.10.10; Box 1 measuring method).
- Ashwell M, Gunn P, Gibson S (2012), "Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors: systematic review and meta-analysis," Obesity Reviews, PubMed.
- Browning LM, Hsieh SD, Ashwell M (2010), "A systematic review of waist-to-height ratio as a screening tool for the prediction of cardiovascular disease and diabetes: 0.5 could be a suitable global boundary value," Nutrition Research Reviews, PubMed.
- Ashwell M, Gibson S (2016), "Waist-to-height ratio as an indicator of 'early health risk'," BMJ Open, PubMed.
- Gibson S, Ashwell M (2020), "A simple cut-off for waist-to-height ratio (0.5) can act as an indicator for cardiometabolic risk," British Journal of Nutrition, PubMed.
- National Heart, Lung, and Blood Institute (NHLBI, NIH), Aim for a Healthy Weight: waist circumference, and CDC, Healthy Weight (measuring method; more than 40 inches for men, more than 35 inches for women).
- CDC, Adult BMI Categories.
- U.S. Army, Army modifies body composition program, adopts waist-to-height ratio (July 7, 2026; benchmark below 0.55, measured at the navel).
- CDC National Center for Health Statistics, NHANES Anthropometry Procedures Manual (2021), waist circumference at the top of the right hip bone.
⚠️ Common mistakes & edge cases
Mixing inches and centimeters
A 36 inch waist divided by a height of 178 cm gives 0.20, a meaningless number. Both measurements must be in the same unit. The calculator converts both numbers for you when you switch between US units and metric.
Measuring at the belt line
Pants often sit below the natural waist, and the size on the label does not have to match a tape measure. Measure on bare skin at the spot described above, and do not use your jeans size as a shortcut.
Pulling the stomach in
Holding your breath or tightening your belly shrinks the reading and makes the ratio look better than it is. Read the tape at the end of a normal breath out, standing relaxed.
Treating 0.50 as "just fine"
The boundary belongs to the increased band. A ratio of 0.50 means your waist has reached half your height; the healthy band ends just below it.
Applying the bands with a BMI of 35 or more
NICE uses the ratio bands only for a BMI under 35. Its committee noted that people above that BMI are always likely to have a high ratio, so the ratio adds little there. The calculator notes this when your optional BMI is 35 or higher.
Expecting the scale to move the ratio
For adults, height is fixed, so only the waist changes the ratio. At 5 ft 10 in each inch off the waist lowers it by about 0.014. Weight lost elsewhere does not show up here at all.
❓ Frequently asked questions
What is a healthy waist to height ratio?
A ratio from 0.40 to 0.49 is the healthy band in NICE guideline NG246, which describes it as healthy central adiposity with no increased health risk. From 0.50 to 0.59 the guideline speaks of increased risk, and at 0.60 or more of further increased risk. The simplest way to remember it: keep your waist to less than half your height.
How do I calculate my waist to height ratio?
Measure your waist and your height in the same unit, then divide the waist by the height. A 36 inch waist at 5 ft 10 in (70 inches) gives 36 ÷ 70 = 0.51. In metric, a 96.5 cm waist at 170 cm gives 0.57. Feet must be converted to inches first: 5 ft 7 in is 67 inches. The ratio has no unit, so inches and centimeters give the same answer.
Is waist to height ratio better than BMI?
For spotting cardiometabolic risk, the research says it usually is. A 2012 meta-analysis of 31 studies with more than 300,000 adults found that the waist-to-height ratio separated people with and without diabetes, high blood pressure and cardiovascular disease significantly better than BMI and better than waist circumference alone. BMI still describes overall body size, so the two work well together.
What does a waist to height ratio of 0.5 mean?
It means your waist is exactly half your height, which is the boundary between the healthy and the increased-risk bands. A 2010 systematic review of 78 studies found mean boundary values of 0.50 for both men and women in studies from 14 countries, which is why 0.5 is used as a single global cutoff. In the calculator, a waist even slightly under half your height counts as below 0.5.
Where exactly should I measure my waist?
NICE recommends finding the bottom of your ribs and the top of your hips and measuring halfway between them, usually just above the belly button, after a normal breath out. NIH and CDC describe a spot just above the hip bones, and the US national survey NHANES uses the top of the hip bone. The spots can give different numbers, so choose one method and use it every time.
Is the 0.5 cutoff the same for men, women and all ethnic groups?
Yes, according to NICE, which applies the same bands to both sexes and all ethnicities, including adults with high muscle mass, as long as BMI is under 35. That is one practical advantage over waist circumference cutoffs, which differ by sex, and over BMI, where NICE lowers the thresholds for several ethnic groups.
Can children use the waist to height ratio?
Yes, from age 5. NICE guideline NG246 recommends considering the waist-to-height ratio for children and young people aged 5 and over and applies the same bands as for adults: 0.40 to 0.49 healthy, 0.50 to 0.59 increased and 0.60 or more high. For children under 5, use the growth charts and BMI-for-age tools instead.
How is waist to height ratio different from waist to hip ratio?
Both look at fat around the middle, but they compare the waist with different things. The waist-to-hip ratio divides the waist by the hips and uses separate cutoffs for men and women. The waist-to-height ratio divides by height, which does not change in adults, and uses one boundary of 0.5 for everyone. The waist-to-hip ratio can shift when hip size changes even if the waist stays the same.
Can I have a healthy BMI and a high waist to height ratio?
Yes, and it is common. In a UK survey of 1,453 adults, 35% of those judged at no increased risk by BMI and waist circumference together had a waist-to-height ratio of 0.5 or more, and adults with a healthy BMI but a ratio of 0.5 or more had some significantly higher cardiometabolic risk factors. A woman at 170 cm and 72 kg has a healthy BMI of 24.9, yet a 96.5 cm waist puts her ratio at 0.57.
What waist-to-height ratio does the Army use?
Since July 2026 the US Army uses a waist-to-height ratio below 0.55 as its body composition benchmark. Soldiers are measured at the navel twice a year, and a result of 0.55 or more gets a confirmation measurement before the Army Body Composition Program applies. That is a military fitness standard, not a health cutoff: a ratio of 0.52 passes the Army screen yet sits in NICE's increased-risk band, which starts at 0.50.
How much do I need to lose from my waist to get under 0.5?
Subtract half your height from your waist. At 5 ft 10 in, half your height is 35 inches, so a 36 inch waist needs to come down by just over 1 inch to get below 0.5, and to 34.3 inches for a ratio of 0.49. Because adult height does not change, the waist is the only part of the ratio that moves.
💡 Good to know
The string check
No calculator at hand? Cut a piece of string as long as you are tall, fold it in half and wrap it around your waist. If the ends meet with string to spare, your ratio is under 0.5.
One inch is worth more for shorter people
Every inch of waist moves the ratio by 1 ÷ your height: about 0.017 at 5 ft 0 in and 0.013 at 6 ft 4 in. Shorter people see their ratio respond faster to the same change.
The same rule from age 5
NICE applies the same three bands to children and young people from age 5 as to adults, so a family can use one simple message: waist less than half of height.