Waist-to-Hip Ratio Calculator

What waist-to-hip ratio (WHR) measures

Waist-to-hip ratio is a two-number comparison: your waist measurement divided by your hip measurement. A 34-inch waist and 42-inch hips give 34 ÷ 42 = 0.81. Because it is a ratio it has no units, so the same answer comes out whether you measure in inches or centimeters.

The point of the ratio is that it describes where you carry weight, not just how much. Two people can weigh exactly the same and have the same body mass index, but if one carries fat around the belly and the other around the hips and thighs, their health outlook is different. Fat stored around the waist sits near the organs, and that is the fat doctors pay attention to. The World Health Organization uses waist-to-hip ratio as one of the cheap, no-equipment screening measures for that risk, and you can read its own summary on the WHO obesity and overweight fact sheet.

This page gives you the number and the published risk bands. It is an estimate for general information only, it is not medical advice, and it cannot see your age, family history, blood pressure or blood work. Treat it as a conversation starter with a doctor, not a verdict.

How to measure your waist and hips correctly

The ratio is only as good as the two numbers you feed it, and most people measure wrong. The mistakes that matter most are measuring the waist down at the navel (too low) or pulling the tape tight enough to squeeze the skin.

• Use a flexible tape. A cloth tailor's tape is ideal. A metal tape measure, or a piece of string you then hold against a ruler, both work.
• Stand up and breathe normally. No sucking in. Let the air out at the end of a normal breath, then read the number.
• Waist: find the narrowest point between the bottom of your rib cage and the top of your hip bone, usually just above the navel. Keep the tape level all the way around.
• Hips: measure at the widest point of your buttocks, usually 7 to 9 inches below the waist. Snug, level, and not compressing the skin.
• Read to the nearest 0.25 inch (0.5 cm). Measure twice. If the two readings differ by more than half an inch, take a third and use the middle value.

Do it first thing in the morning, before eating, wearing as little as practical, and measure the same way each time, consistency is what makes a trend useful. The CDC's guidance on assessing your weight covers the same tape-measure basics for waist circumference.

Worked examples with real numbers

Here is what the arithmetic looks like on three sets of measurements.

Example 1, 34-inch waist, 42-inch hips. 34 ÷ 42 = 0.81. For a woman the threshold is 0.85, so 0.81 sits inside the healthy band. For a man the threshold is 0.90, so the same 0.81 is comfortably low. Same body, two different readings, because the bands differ by sex.

Example 2, 38-inch waist, 41-inch hips. 38 ÷ 41 = 0.93. For a woman that is above the 0.85 threshold and above the 0.90 high-risk line, so it reads as high risk. For a man 0.93 is above 0.90 but below 0.95, so it reads as increased risk. A 4-inch change in the waist, from 34 to 38, moved the ratio from 0.81 to 0.93. The waist measurement, not the hip one, does most of the work.

Example 3, metric. A 92 cm waist and 108 cm hips give 92 ÷ 108 = 0.852. That is a 36.2-inch waist and 42.5-inch hips, and 36.2 ÷ 42.5 = 0.852 too. Same ratio, as it must be. For a woman 0.852 just edges past the 0.85 line; for a man it is well inside the healthy range.

Risk ranges at a glance

The thresholds below are the ones most widely used for adults, and they are screening bands rather than a diagnosis.

These match the cut-offs the WHO uses for 'substantially increased risk' in adults, 0.90 for men and 0.85 for women. Some older papers publish different bands (0.95 for men and 0.80 for women), so a 0.01 difference should not worry you. A woman at 0.86 is not dramatically different from a woman at 0.84; both mean she is right around the line. What matters more is the direction of travel over months, not the decimal on any single morning.

Waist circumference on its own carries its own thresholds, and the US National Heart, Lung, and Blood Institute lists them in its guidance on assessing overweight and obesity. In short: about 35 inches for women and 40 inches for men marks substantially increased risk regardless of what the ratio says.

WHR vs BMI vs waist circumference

Three numbers describe body size and shape, and they answer different questions. That is why a doctor may write down all three.

A muscular person can have a BMI of 28 and a waist-to-hip ratio of 0.85, which reads differently from a person of the same weight with a ratio of 1.02. That gap is exactly why BMI alone is not the whole story. If you want the height-and-weight side of the picture, our BMI prime calculator does the same job using the same inputs.

For people who are short or tall, BMI drifts a little because weight does not scale perfectly with the square of height. Waist-to-hip ratio does not care about your height at all, which is one reason it is often quoted alongside BMI rather than instead of it.

What to do with your number

A single ratio is a snapshot, and snapshots are noisy. Measure monthly, same time of day, same tape, and write the numbers down. If your ratio is climbing over three or four readings, that trend is more informative than any one value.

If your ratio sits in the increased or high band, the useful next step is not panic, it is a check-up. Ask your doctor about blood pressure, fasting glucose, cholesterol and waist circumference, because those together give a far clearer picture than any tape measure alone. Around 5 to 10% of body weight is the loss that usually shows up first around the waist, and adding two or three walks a week plus some strength work is the boring answer that moves the number.

Two things this tool cannot do. It cannot tell you whether you are healthy, only a clinician with your history and lab results can. And it cannot adjust for pregnancy, recent surgery, or athletes with unusual muscle mass, where waist and hip measurements behave differently. This is an estimate for general information only, not medical advice. Confirm anything important with a qualified professional before you act on it.