What the waist-to-hip ratio shows
The waist-to-hip ratio, or WHR, compares the circumference of your waist with the circumference of your hips. You divide one by the other, so a waist of 32 inches and hips of 40 inches give 32 ÷ 40 = 0.80. A higher number means more of your size sits around the middle compared with the hips. The National Heart, Lung, and Blood Institute notes that people who carry most of their fat around the waist are at higher risk for heart disease and type 2 diabetes, and the waist-to-hip ratio is one simple way to put a number on that with nothing more than a tape measure.
The World Health Organization held an expert consultation on waist circumference and the waist-hip ratio in Geneva in December 2008 and published its report in 2011. It reviewed how to measure both, how they vary by sex, age and ethnicity, how well they predict the risk of cardiovascular disease, diabetes and overall mortality, and how they relate to BMI. The cut-offs in this calculator come from that report.
The WHO cut-offs
The WHO report gives one cut-off for men and one for women. At or above it, the waist-to-hip ratio marks a substantially increased risk of metabolic complications.
| Sex | Waist-to-hip ratio | Risk of metabolic complications |
|---|---|---|
| Men | 0.90 or more | Substantially increased |
| Women | 0.85 or more | Substantially increased |
The calculator shows your ratio rounded to two decimals and compares that number with the cut-off, so a ratio shown as 0.85 counts as at the cut-off for women. It also works out the largest waist that keeps your ratio below the cut-off for your hip size. That is plain arithmetic, not a target: losing or gaining weight changes both measurements, and a doctor can tell you what a healthy goal looks like for you.
A waist measurement on its own is another common check. The National Heart, Lung, and Blood Institute (NHLBI) says that a waist of more than 40 inches for men or more than 35 inches for women increases your risk. The calculator shows that check next to the ratio.
How to measure your waist and hips
Small differences in where the tape sits change the ratio, so it pays to measure the same way every time. The WHO STEPS surveillance manual, which the WHO uses for its population surveys, describes these steps:
- Measure over bare skin if you can, or over light clothing. Take off thick or bulky clothes.
- Stand with your feet together, your weight evenly on both feet and your arms relaxed at your sides.
- For the waist, find the lowest rib you can feel and the top of your hip bone, and place the tape at the midpoint between the two, on both sides of your body.
- Breathe normally for a few breaths, then measure at the end of a normal breath out.
- For the hips, place the tape around the widest part of your buttocks.
- Keep the tape level all the way around and snug, but not so tight that it presses into the skin. The manual reads the tape to the nearest 0.1 cm.
Use the same unit for both measurements. The ratio is the same in inches and centimeters, because the unit cancels out when you divide.
Waist-to-hip ratio, waist size and BMI
The BMI calculator compares your weight with your height. It cannot tell where fat sits or how much muscle you carry. The waist-to-hip ratio adds that missing piece: two people with the same BMI can have quite different ratios. The WHO STEPS manual notes that waist circumference or the waist-to-hip ratio are powerful determinants of later risk of type 2 diabetes. For an estimate of how much of your weight is fat, the body fat calculator uses a tape measure too.
None of these numbers is a diagnosis. They are screening measures that help you and your doctor decide whether a closer look is worthwhile. The WHO report itself looked at differences by age and ethnicity, so a single cut-off cannot fit every person equally well. Pregnancy changes the waist, and WHO STEPS surveys skip the waist and hip measurements for pregnant women, so the ratio is not meant for that time. If you are worried about your result, talk to your doctor.
How to use the waist-to-hip ratio calculator
- 1Choose inches or centimeters and pick female or male, since the WHO cut-off differs by sex.
- 2Measure your waist and hips as described above and enter both numbers.
- 3Read your ratio, where it sits against the WHO cut-off, the largest waist below the cut-off for your hips, and the NHLBI waist check. Copy the result or a link.
Sources
- Waist circumference and waist-hip ratio: report of a WHO expert consultation, Geneva, 8 to 11 December 2008, World Health Organization, 2011. Waist-hip ratio cut-offs for a substantially increased risk of metabolic complications.
- The WHO STEPwise approach to noncommunicable disease risk factor surveillance (STEPS) manual, World Health Organization. Part 3, Section 5, Measuring Waist Circumference and Measuring Hip Circumference, last updated 26 January 2017.
- Aim for a healthy weight: assessing your risk, National Heart, Lung, and Blood Institute (NHLBI), NIH. Waist circumference above 40 inches for men and 35 inches for women, and fat around the waist.
Frequently asked questions
What is a good waist-to-hip ratio?
The WHO expert consultation on waist circumference and waist-hip ratio gives one cut-off for each sex: a ratio of 0.90 or more in men and 0.85 or more in women marks a substantially increased risk of metabolic complications. Below that cut-off, the ratio does not point to that increased risk. It is a screening measure, not a diagnosis, so talk to your doctor about what your numbers mean for you.
How do I measure my waist and hips for the ratio?
The WHO STEPS protocol measures the waist at the midpoint between the lowest rib you can feel 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. Stand with your feet together and your arms relaxed, keep the tape level and snug without pressing into the skin, and measure over bare skin or light clothing.
Does it matter if I measure in inches or centimeters?
No, as long as both measurements use the same unit. The ratio is the waist divided by the hips, so the unit cancels out: 34 in and 40 in give 0.85, and so do 86.4 cm and 101.6 cm. Switch the unit in the calculator and your numbers are converted.
Why are the cut-offs different for men and women?
The WHO expert consultation looked at how waist and hip measures vary by sex, age and ethnicity, and its report gives a separate cut-off for each sex: 0.90 for men and 0.85 for women. Pick the sex that applies to you, and the calculator compares your ratio with the matching cut-off.
Is the waist-to-hip ratio better than BMI?
They measure different things. BMI compares weight with height and says nothing about where fat sits. The waist-to-hip ratio looks at how weight is distributed around the middle. The WHO STEPS manual notes that waist circumference or the waist-to-hip ratio are powerful determinants of later risk of type 2 diabetes. You can look at both, and your doctor can help you read them together.
Can I use this during pregnancy?
It is not meant for pregnancy. The waist grows with the baby, and in WHO STEPS surveys pregnant women skip the waist and hip measurements altogether.
Are my measurements stored or sent anywhere?
No. The calculation runs in your browser and nothing is sent or saved. If you copy a share link, your measurements, the unit and the sex you picked become part of that link, so share it only where you want.