Measuring your Body: BMI Calculation & Waist Circumference

There are two tools you can use to assess whether there is a health risk relating to your body size. Body mass index (BMI), and waist circumference. Used together, these two measures can give you a good indication of your overall health risk.

Body Mass Index Calculation (BMI)

Body Mass Index (BMI) is a useful measure of your body fat based on your weight and height. The higher your BMI, the greater your risk of developing conditions such as heart disease, type 2 diabetes, and high blood pressure.

Your BMI is calculated by taking your weight and dividing it by your height squared. This sounds complicated, but there are many online BMI calculators that do the math for you!

A high BMI can be an indicator of high body fat, and a low BMI can indicate low body fat.

How to calculate your BMI?

Measure your height and weight and use a BMI Calculator or BMI Table.

Your BMI score means the following:

BMI (kg/m2) Weight Status
Below 18.5 Underweight
18.5 – 24.9 Normal or Healthy Weight
25.0 – 29.9 Overweight
30.0 – 34.9 Obese Class I
35.0 – 39.9 Obese Class II
≥40.0 Obese Class III


It is important to know that the BMI is a useful screening tool for adult men and women, but it does have some limitations. It may overestimate body fat in athletes and people with a muscular build and may underestimate body fat in older people and those who have lost muscle.

Waist Circumference Measurement

Your waist circumference measures your abdominal fat. If you have most of your fat distributed around your waist rather than your hips, you have a higher risk for developing conditions like heart disease, type 2 diabetes, and other obesity-related conditions.

This risk goes up if you are:

  • A man whose waist circumference is greater than 40 inches
  • A non-pregnant woman whose waist circumference is greater than 35 inches

How to measure your waist circumference?

Stand and place a tape measure around your middle level with your belly button. Don’t pull the measure too tight, and don’t hold your breath while measuring. Measure your waist just after you breathe out.

What do the results mean?

If your BMI is 30 or more, or between 25-29.9 with two or more risk factors (i.e., high blood pressure, diabetes) it is recommended that you lose weight. If your waist measurement is larger than 40 inches for men, and 35 inches for women, you may want to talk with your doctor to assess your health risks.

The good news is that losing as little as 5-10 percent of your body weight can have a positive effect on your health!

Note that BMI and Waist circumference can be used as a screening tool but are not diagnostic of the health of an individual.

Diagnosis needs appropriate health assessments by your health care provider to evaluate your health status and risks.

Medical Disclaimer
The articles provided on this website are for informational purposes only. In addition, it is written for a generic audience and not a specific case; therefore, this information should not be used for diagnostic or medical treatment. This site does not attempt to replace the patient-physician relationship and fully recommends the reader to seek out the best care from his/her physician and/or diabetes educator.


  3. BMI calculator –