Waist to Height Ratio Calculator
Keep your waist to less than half your height. Check your waist-to-height ratio against NICE health categories, see the healthy waist size for your exact height, compare with Army and Marine Corps standards, and get your Body Roundness Index in the same step.
Written and fact-checked by Manzoor Ahmad, Pharm-DLast reviewed September 29, 2026
Enter your height and waist to see your waist-to-height ratio. Everything runs in your browser and nothing is stored.
Your waist-to-height ratio
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The string test
A string cut to your height, folded in half, should fit around your waist. The dark line marks half your height.
Where you fall
The marker is you. Thin lines show the Marine Corps (0.52) and Army and Navy (0.55) standards.
Waist-to-height ratio
Body Roundness Index
What your number means
Your waist plan
What is waist-to-height ratio?
Waist-to-height ratio (WHtR) is your waist circumference divided by your height, measured in the same units. A 34-inch waist on a 68-inch person gives a ratio of 0.50. The simple public health message is: keep your waist to less than half your height.
The UK’s National Institute for Health and Care Excellence (NICE) groups adults this way: 0.40 to 0.49 is healthy central adiposity, 0.50 to 0.59 means increased health risk, and 0.60 or higher means high health risk. The same boundaries apply to men and women and across ethnic groups, which is one of the biggest advantages of this measure over BMI and waist size alone.
How to use the waist to height ratio calculator
- Choose your units and enter sex and age. Neither changes the 0.5 boundary, but they shape the advice you see, especially for children, teenagers and adults over 65.
- Measure your height barefoot against a wall and enter it in feet and inches or centimeters.
- Measure your waist midway between your lowest rib and the top of your hip bone, at the end of a normal breath out, and enter it.
- Add your weight if you like. It is only used for a BMI cross-check, because NICE suggests using both measures together for people with a BMI under 35.
- Read the string test and the zone bar. They show at a glance whether your waist fits within half your height, and how you compare with military standards.
The string test: a waist-to-height check without a calculator
Cut a piece of string to your exact height. Fold it in half and wrap it around your waist at the measuring point. If the ends meet or overlap, your waist is less than half your height and your ratio is below 0.5. If they do not meet, your ratio is above 0.5. The calculator’s string test panel shows the same thing with your real numbers, so you can see how much string is left over or missing.
Waist-to-height ratio chart by height
Find your height to see the waist sizes that mark each NICE boundary. A waist below the middle column keeps your ratio under 0.50.
| Height | Waist at 0.40 | Waist at 0.50 (keep below) | Waist at 0.60 (high risk) |
|---|---|---|---|
| 4’10” (147 cm) | 23.2 in (59 cm) | 29.0 in (74 cm) | 34.8 in (88 cm) |
| 4’11” (150 cm) | 23.6 in (60 cm) | 29.5 in (75 cm) | 35.4 in (90 cm) |
| 5’0″ (152 cm) | 24.0 in (61 cm) | 30.0 in (76 cm) | 36.0 in (91 cm) |
| 5’1″ (155 cm) | 24.4 in (62 cm) | 30.5 in (77 cm) | 36.6 in (93 cm) |
| 5’2″ (157 cm) | 24.8 in (63 cm) | 31.0 in (79 cm) | 37.2 in (94 cm) |
| 5’3″ (160 cm) | 25.2 in (64 cm) | 31.5 in (80 cm) | 37.8 in (96 cm) |
| 5’4″ (163 cm) | 25.6 in (65 cm) | 32.0 in (81 cm) | 38.4 in (98 cm) |
| 5’5″ (165 cm) | 26.0 in (66 cm) | 32.5 in (83 cm) | 39.0 in (99 cm) |
| 5’6″ (168 cm) | 26.4 in (67 cm) | 33.0 in (84 cm) | 39.6 in (101 cm) |
| 5’7″ (170 cm) | 26.8 in (68 cm) | 33.5 in (85 cm) | 40.2 in (102 cm) |
| 5’8″ (173 cm) | 27.2 in (69 cm) | 34.0 in (86 cm) | 40.8 in (104 cm) |
| 5’9″ (175 cm) | 27.6 in (70 cm) | 34.5 in (88 cm) | 41.4 in (105 cm) |
| 5’10” (178 cm) | 28.0 in (71 cm) | 35.0 in (89 cm) | 42.0 in (107 cm) |
| 5’11” (180 cm) | 28.4 in (72 cm) | 35.5 in (90 cm) | 42.6 in (108 cm) |
| 6’0″ (183 cm) | 28.8 in (73 cm) | 36.0 in (91 cm) | 43.2 in (110 cm) |
| 6’1″ (185 cm) | 29.2 in (74 cm) | 36.5 in (93 cm) | 43.8 in (111 cm) |
| 6’2″ (188 cm) | 29.6 in (75 cm) | 37.0 in (94 cm) | 44.4 in (113 cm) |
| 6’3″ (190 cm) | 30.0 in (76 cm) | 37.5 in (95 cm) | 45.0 in (114 cm) |
| 6’4″ (193 cm) | 30.4 in (77 cm) | 38.0 in (97 cm) | 45.6 in (116 cm) |
| 6’5″ (196 cm) | 30.8 in (78 cm) | 38.5 in (98 cm) | 46.2 in (117 cm) |
| 6’6″ (198 cm) | 31.2 in (79 cm) | 39.0 in (99 cm) | 46.8 in (119 cm) |
Applies to adults of any sex or ethnicity. Swipe sideways on a phone.
Waist-to-height ratio categories explained
| WHtR | Category | What it suggests |
|---|---|---|
| Below 0.40 | Take care | Very slim waist for your height. Fine for many people, but in older adults or those losing weight unintentionally it can signal low muscle or poor nutrition. |
| 0.40 to 0.49 | Healthy | Healthy central fat level. Keep it here. |
| 0.50 to 0.59 | Increased risk | More fat around the middle, linked with higher blood pressure, blood sugar and cholesterol risk. |
| 0.60 and above | High risk | Strong signal of visceral fat and cardiometabolic risk. Worth a health check. |
A healthy waist-to-height ratio for women and a healthy waist-to-height ratio for men are the same: under 0.5. That makes WHtR unusually easy to remember and to explain to family members.
Waist-to-height ratio for children and teenagers
Researchers have proposed 0.5 as a practical boundary for children from about age 6 too, because it holds up better across ages than BMI. It is not yet a formal diagnostic cut-off for young people, so the calculator shows a result for ages 6 to 17 with a note to discuss it with a pediatrician rather than acting on it alone.
Waist-to-height ratio vs BMI, waist-to-hip ratio and BRI
A 2012 systematic review and meta-analysis by Ashwell and colleagues, pooling data from more than 300,000 adults, found waist-to-height ratio was a better screening tool for cardiometabolic risk than either waist circumference or BMI. It needs only a tape measure, works for people of different heights, and avoids the BMI trap of labeling muscular people as overweight.
Waist-to-height ratioOne tape, one simple rule, same boundary for everyone. Best single home screen for belly fat risk.
BMIWeight for height. Misses fat distribution and muscle. Check it with the BMI calculator.
Waist-to-hip ratioShows apple versus pear shape but needs two measurements and can be skewed by hip size. Try the waist to hip ratio calculator.
Body Roundness Index (BRI)Uses the same waist and height to model body shape as an ellipse. It gets a lot of attention because of a 2024 mortality study, and this calculator gives it to you automatically.
Body Roundness Index formula and ranges
Waist and height in metersBRI = 364.2 − 365.5 × √(1 − (waist ÷ 2π)² ÷ (0.5 × height)²)
In a 2024 JAMA Network Open study of nearly 33,000 US adults, the link between BRI and death from any cause was U-shaped. The middle group, with a BRI of about 4.45 to 5.45, had the lowest risk. Risk was about 25 percent higher below 3.41 and about 49 percent higher at 6.91 or above. BRI is useful context, but WHtR remains the simpler, guideline-backed number.
Military waist-to-height ratio standards
Waist-to-height ratio has moved from public health into military fitness. As of 2026, the Army uses a pass line below 0.55 as its only body composition standard, recorded to three decimals without rounding. The Navy also uses 0.55, and the Marine Corps set a stricter 0.52. The zone bar in this calculator marks both lines. If you are serving or preparing to, the Army body fat calculator shows the exact largest passing waist for your height and how a re-measurement could change your result.
A pharmacist’s view on waist size
In practice I find waist-to-height ratio the most useful single number to hand someone. It is easy to measure at home, it does not depend on a scale, and it responds to the changes that matter for blood sugar and blood pressure.
When a rising waist is really a medicine question
Long-term corticosteroids, some antipsychotics, insulin and certain older HIV medicines can build fat around the middle. Menopause, poor sleep, chronic stress and heavy drinking do the same. If your waist is growing while your habits have not changed, bring your medicine list to your doctor or pharmacist. Never stop a prescribed medicine on your own.
What moves the ratio in the right direction
Visceral fat tends to respond early to overall fat loss, so a modest calorie deficit, daily walking, two or more strength sessions a week, more fiber and less alcohol often shrink the waist before the scale shows much change. GLP-1 medicines such as semaglutide and tirzepatide reduce visceral fat as part of weight loss, but they need a prescriber and a plan to protect muscle, which you can track with the lean body mass calculator.
Skip the belly-fat supplements
No capsule targets waist fat. Products marketed that way usually rely on stimulants, diuretics or laxatives that change the mirror for a day, not your visceral fat. Save the money for a good tape measure and walking shoes.
Limitations of waist-to-height ratio
- Pregnancy makes the measurement meaningless until well after birth.
- Measuring site changes the number. The navel often reads a little larger than the NICE midpoint. Stick to one site when tracking.
- Very short or very tall adults may sit at the edges of the evidence, though WHtR handles height better than waist circumference alone.
- Older adults with a very low ratio may be losing muscle. A low number is not automatically a good one.
- It does not measure fitness. Pair it with activity, blood pressure and blood tests for a full picture, and use the ideal weight calculator if you want a weight target to go with your waist goal.
Waist to height ratio calculator FAQ
Divide your waist circumference by your height, using the same units for both. For example, a 32-inch waist and a 66-inch height give 32 ÷ 66 = 0.48. Measure the waist midway between your lowest rib and the top of your hip bone after a normal breath out.
A healthy waist-to-height ratio is 0.40 to 0.49. NICE classes 0.50 to 0.59 as increased health risk and 0.60 or higher as high health risk. The simple rule is to keep your waist to less than half your height.
Yes. The 0.5 boundary applies to both men and women, and NICE applies it across ethnic groups as well. This makes it simpler than waist circumference, which uses different cut-offs by sex and ancestry.
Multiply your height by 0.5. At 5 feet 4 inches (64 inches) your waist should be under 32 inches, at 5 feet 10 inches (70 inches) under 35 inches, and at 6 feet (72 inches) under 36 inches. In centimeters, a 170 cm person should keep their waist under 85 cm.
For predicting heart and metabolic risk, research suggests it often is. A 2012 meta-analysis of more than 300,000 adults found waist-to-height ratio outperformed both BMI and waist circumference. NICE recommends using it alongside BMI for adults with a BMI under 35.
Cut a string to your height, fold it in half and wrap it around your waist. If the ends meet or overlap, your waist is less than half your height and your ratio is below 0.5.
A ratio of 0.60 or higher is classed as high health risk. It strongly suggests excess visceral fat, which is linked with type 2 diabetes, high blood pressure and heart disease, and is worth discussing with a doctor.
A ratio below 0.40 is usually fine in younger healthy adults, but in older adults or people losing weight without trying it can signal muscle loss or undernutrition. A low ratio is not automatically better.
The US Army uses a waist-to-height ratio below 0.55 as its body composition standard under Army Directive 2026-13, recorded to three decimals without rounding. The Navy also uses 0.55 and the Marine Corps uses 0.52.
The Body Roundness Index (BRI) uses waist and height to model body shape as an ellipse. In a 2024 study of nearly 33,000 US adults, a BRI of about 4.45 to 5.45 was linked with the lowest mortality risk, with higher risk at both very low and high values.
Researchers have proposed 0.5 as a boundary for children from about age 6, and it holds up across ages better than BMI. It is not yet a formal diagnostic cut-off for young people, so results should be discussed with a pediatrician.
Reduce overall body fat with a moderate calorie deficit, daily activity, strength training, more fiber, less alcohol and good sleep. Visceral fat often responds early, so your waist can shrink before the scale changes much. Spot exercises alone do not target belly fat.
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About the author
Manzoor Ahmad, Pharm-D
Pharmacist, health content writer and founder of DexoCalc
Manzoor is a Doctor of Pharmacy with more than nine years of experience writing about supplements, weight management and medication safety. He runs a community pharmacy where questions about belly fat, medicines that cause weight gain and weight-loss supplements come up every week. He built this calculator from the original published equations and checks every formula against worked examples before release.
Sources and references
- National Institute for Health and Care Excellence. Obesity: identification, assessment and management (waist-to-height ratio recommendations, updated 2022). London: NICE.
- Ashwell M, Gunn P, Gibson S. 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. 2012;13(3):275-286.
- Ashwell M, Gibson S. Waist-to-height ratio as an indicator of early health risk: simpler and more predictive than using a matrix based on BMI and waist circumference. BMJ Open. 2016;6(3):e010159.
- Thomas DM, Bredlau C, Bosy-Westphal A, et al. Relationships between body roundness with body fat and visceral adipose tissue emerging from a new geometrical model. Obesity. 2013;21(11):2264-2271.
- Zhang X, Ma N, Lin Q, et al. Body Roundness Index and all-cause mortality among US adults. JAMA Network Open. 2024;7(6):e2415051.
- McCarthy HD, Ashwell M. A study of central fatness using waist-to-height ratios in UK children and adolescents over two decades supports the simple message: keep your waist circumference to less than half your height. International Journal of Obesity. 2006;30(6):988-992.
- U.S. Army. Army Directive 2026-13, Army Body Composition Program and Standards. July 2026.
This waist to height ratio calculator is for education and general wellness. Risk categories are population-based and cannot diagnose any condition. It is not a diagnosis and not a substitute for advice from your doctor, pharmacist or dietitian, especially if you are pregnant, under 18, or have symptoms or a diagnosed medical condition.