How to Measure Your Waist

Medically Reviewed by Zilpah Sheikh, MD on July 19, 2024
Written by WebMD Editorial Contributors
6 min read

It’s easy to measure your waist. And it’s not just about your clothing size. Your waist circumference is a clue to whether you're at higher risk for type 2 diabetes, high blood pressure, high cholesterol, and heart disease. And all you need is a tape measure:

  • Put the tape measure at the top of your hip bone, then bring it all the way around your body, level with your belly button.
  • Make sure it's not too tight and that it's straight, even at the back. Don't hold your breath or pull in your belly while measuring.
  • Check the number on the tape measure right after you exhale.

What's considered a healthy waist size may vary depending on your gender, height, frame, age, and ethnicity. Different health organizations use different methods to assess whether someone has unhealthy amounts of fat around their middle (called abdominal obesity). These methods include:

  • Waist circumference alone
  • Waist-to-hip ratio
  • Waist-to-height ratio 

 

Your waist size is a good indicator of how much fat you carry in your belly area. Several large studies have shown a strong link between abdominal obesity and a higher risk of high blood pressure, high cholesterol, heart disease, and type 2 diabetes. This was true even for people whose body mass index (BMI) was at a level considered healthy.

What is visceral fat?

Part of the fat around your belly is what's called visceral fat, which surrounds your liver and other organs in your abdomen. This type of fat is metabolically active, releasing fats, hormones, and other inflammatory chemicals into your blood. This ongoing inflammation is thought to play a role in many chronic diseases, including heart disease and diabetes.

Waist size and heart disease

High levels of belly fatraise your risk for several conditions linked to heart and blood vessel (cardiovascular) disease, including high blood pressure, high blood sugar, and high cholesterol. Unhealthy levels of belly fat can also lead to fatty liver disease, another risk factor for cardiovascular disease. 

Waist size and diabetes

The inflammatory hormones produced by visceral fat are thought to lead to insulin resistance, which means your body doesn't respond to the hormone insulin as it should. Insulin resistance can result in high blood sugar, prediabetes, and type 2 diabetes.

Experts agree that excess belly fat is dangerous for your health. But major health organizations use different methods to determine healthy waist size.

The National Heart, Lung and Blood Institute (NHLBI), International Diabetes Federation (IDF), and American Heart Institute (AHI) consider only waist measurement. The NHLBI and AHI define a healthy waist size as:

  • 35 inches or less for women
  • 40 inches or less for men

The IDF says it's:

  • 31.5 inches or less for women (31.4 inches for Chinese, Japanese, and South Asian women)
  • 35.5 or less for men (35.4 inches for Chinese, Japanese, and South Asian men)

 Waist-to-hip ratio

The World Health Organization (WHO) measures abdominal obesity by waist-to-hip ratio, which is a measure of how big your waist is in relation to your hips. WHO defines abdominal obesity as a ratio of more than 0.85 for women and 0.9 for men.

To find your waist-to-hip ratio:

  • Use a measuring tape to measure your waist at its narrowest point.
  • Then measure around your hips at their widest point (where your butt sticks out the most).
  • Divide your waist measurement by your hip measurement.

The resulting number is your waist-to-hip ratio.

Waist-to-height ratio

Both waist measurement and waist-to-hip ratio can vary a lot among people of different genders, ages, and ethnicities. That's why some experts believe waist-to-height ratio is the most consistent way to measure belly fat.

To determine your waist-to-height ratio:

  • Use a ruler or measuring tape to measure your height from the bottom of your feet to the top of your head.
  • Follow the instructions above for how to measure waist size using a measuring tape.
  • Divide your waist measurement in inches by your height measurement in inches to get the ratio.

A ratio over 0.5 (meaning your waist measurement is more than half your height) means you're at higher risk for health problems. 

You can do this even if you don't have a tape measure. All you need is a long piece of string.

  • Measure your height against the string.
  • Then cut the string at the level of the top of your head, so it's the same length you are.
  • Fold the string in half, then wrap it around your waist.

If the folded string won't go all the way around your waist, you likely have unhealthy levels of belly fat.

Waist size and BMI

The BMI is a formula based on your weight and height that doctors sometimes use as a quick way to assess whether your weight is at a healthy level. If your BMI is over 25, you may be considered overweight.

But BMI is an imperfect measure. It's based mostly on information from white males and doesn't allow for differences in gender, race, or ethnicity. It can be inaccurate, especially for people with lots of muscle mass or those who are very tall or short.

A high BMI doesn't always mean your health is at risk. And a larger waist doesn't necessarily equal a higher BMI. That's why some doctors consider waist size — or waist size together with BMI — to be a better measure of health risks than BMI alone.

One large study found that even women with BMIs under 25 were at a higher risk of dying in middle age if they carried more fat around their waists. "Normal weight" women whose waists were 35 inches or larger were three times more likely to die of heart disease than "normal weight" women with smaller waists.

You can’t spot-reduce your waist or any other part of your body.

Crunches and other core exercises can strengthen your abs. But to lose inches around your waist, you'll need to lose weight by eating fewer calories and burning more off through exercise.

Your waist size is a good indication of how much fat you carry in your belly area. People with excess belly fat have a higher risk of conditions such as high blood pressure, high cholesterol, heart disease, and type 2 diabetes. Many health experts believe waist measurement alone is enough to tell whether you have abdominal obesity, but others also take your height or hip measurement into account.

How is the waist measured?

You use a measuring tape, held flat against your skin, to measure your waist at its smallest point. Don't hold your breath or suck in your stomach.

What is a normal waist size?

A "normal" waist size for youvaries depending on many things, including your gender, height, frame, age, and ethnicity. Some health organizations define a healthy waist size very generally as 35 inches or less for women or 40 inches or less for men. Other experts also take height or hip measurements into consideration.

Does waist size determine body fat?

It's possible to have a large waist without being overweight. Even if your overall weight is at a level considered healthy, extra belly fat raises your risk for health problems like heart disease and diabetes.

What is a healthy waist size for my height?

In general, doctors say a healthy waist measurement is one that's half your height or less.