To measure your waist, place a flexible tape around your midsection at the top of your hip bones. To measure your hips, wrap the tape around the widest point of your buttocks and hips. Both measurements should be taken while standing, with the tape level and parallel to the floor. Getting these right matters: your waist-to-hip ratio is a stronger predictor of mortality risk than BMI, based on analyses of nearly 388,000 participants in the UK Biobank.
Where Exactly to Measure Your Waist
Your waist measurement isn’t taken where your belt sits or where your pants button. The standard protocol used in national health surveys locates a specific bone first: the top of your iliac crest, which is the uppermost edge of your hip bone on your right side. You can find it by placing your hands on your hips and pressing inward until you feel the bony ridge. The tape goes horizontally around your abdomen at that level.
The World Health Organization uses a slightly different landmark: the midpoint between your lowest rib and the top of your hip bone. To find this, press your fingers along your side until you feel the bottom of your ribcage, then find the top of your hip bone, and split the difference. In practice, these two spots are often within an inch of each other, but the difference can affect your reading. Pick one method and use it consistently so you can track changes over time.
Where Exactly to Measure Your Hips
Hip circumference is measured at the widest horizontal point around your hips and buttocks. Stand with your feet together and wrap the tape around the largest lateral extension of your hips. This is typically at the level of the bony bumps near the top of your thigh bones, right around where your buttocks protrude the most when viewed from the side. If you’re unsure you’ve found the widest spot, take the measurement at a few slightly different heights and use the largest number.
Step-by-Step Technique
You’ll need a flexible, non-stretchy measuring tape. Fiberglass tapes are ideal because they don’t stretch over time. Vinyl-coated cloth tapes also work well. Avoid cheap plastic tapes, which can gradually lose accuracy. If your tape has a reinforced metal tip, it’s easier to hold in place when measuring yourself.
For both measurements, follow this process:
- Remove clothing from the area, or wear only one thin layer. Bulky fabric adds to your reading, and bunched-up material can shift the tape out of position.
- Stand up straight with your shoulders back, arms relaxed at your sides, and feet together.
- Position the tape so it’s level all the way around, parallel to the floor. A tape that dips in the back will give you a smaller, inaccurate number.
- Check the tension. The tape should sit snugly against your skin without compressing it. If it leaves an indent or digs in, it’s too tight. If you can easily slide a finger underneath, it’s too loose.
- Breathe in, then exhale naturally and let your abdomen fully relax before reading the number. Don’t hold your breath or suck in your stomach.
For your waist, stand facing a mirror if possible so you can confirm the tape is level in front. For your hips, it helps to check your positioning in a side-view mirror to make sure the tape crosses the widest point of your buttocks.
Calculating Your Waist-to-Hip Ratio
Divide your waist measurement by your hip measurement. If your waist is 30 inches and your hips are 33 inches, your ratio is 30 รท 33 = 0.91. The units don’t matter as long as both measurements use the same one (both in inches or both in centimeters).
The WHO considers a ratio above 0.85 for women and above 0.90 for men to indicate increased health risk, particularly for cardiovascular disease and metabolic conditions. A 2023 study published in JAMA Network Open found that waist-to-hip ratio was linked more strongly and consistently with risk of death from any cause than BMI or other body fat measures. The researchers used a genetic analysis method called mendelian randomization, which suggested the relationship between a higher ratio and mortality is likely causal, not just a correlation.
Common Mistakes That Skew Your Numbers
Research on measurement error has identified several factors that reliably throw off waist and hip readings. The biggest ones are easy to fix once you know about them.
Measuring over clothing is the most common source of error, sometimes adding a full inch or more depending on the fabric. Compressing the skin with a too-tight tape is equally problematic in the opposite direction, giving you a falsely small number. Both mistakes are avoidable by checking that the tape touches your skin without leaving a mark.
Posture matters more than people expect. Slouching pushes abdominal tissue forward and can inflate your waist reading. Standing with your weight shifted to one leg changes the widest point of your hips. Stand straight with your weight evenly distributed on both feet.
Breathing phase also changes the result. Your waist measurement taken during a deep inhale can differ noticeably from one taken after a full exhale. The standard is to breathe out naturally, let your belly relax completely, and read the tape at that point. Don’t forcefully exhale or brace your core.
Finally, timing relative to meals can affect your waist reading. A large meal temporarily distends the abdomen. For the most consistent tracking, measure at the same time of day, ideally in the morning before eating.
Waist Circumference on Its Own
Even without calculating a ratio, your waist measurement alone carries useful health information. It reflects visceral fat, the fat stored around your internal organs, which is more metabolically active and more strongly linked to cardiovascular and metabolic disease than fat stored in the hips or thighs. General thresholds for increased risk are a waist circumference above 35 inches (88 cm) for women and above 40 inches (102 cm) for men.
If you’re tracking your measurements over time for fitness or health goals, consistency in technique matters more than hitting any single number. Measure at the same spot, same time of day, with the same tape, using the same breathing pattern. Small variations between individual readings are normal. What you’re looking for is the trend across weeks and months.