BMI Calculator & Waist Obesity Check
Last updated: 2026-06-25
BMI = weight (kg) ÷ height (m)². Using Asian-Pacific cutoffs, 18.5-22.9 is normal, 23 and up is overweight, and 25 and up is obesity.
The waist threshold for abdominal obesity is 90 cm or more for men and 85 cm or more for women. Results are for reference only, not a diagnosis.
Enter height, weight and waist
Body mass index (BMI)
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BMI uses only height and weight, so it does not reflect muscle mass or fat distribution. This result is for reference only, not a diagnosis. A full assessment, including body fat percentage, is made by a clinician. For more on BMI see the CDC Healthy Weight resources.
How to use
- Enter height and weight — type your height (cm) and weight (kg).
- Enter sex and waist — for the abdominal obesity check, choose your sex and enter your waist (cm). Waist is optional.
- View the result — press Calculate to see the BMI value and category, plus the abdominal obesity result when waist is entered.
BMI classification and the waist threshold
Body mass index (BMI) is weight (kg) divided by height (m) squared, a simple estimate of obesity level. For example, 170 cm and 65 kg gives a BMI of 65 ÷ (1.70)² ≈ 22.5, which is normal. The chart below uses Asian-Pacific cutoffs. (The WHO international cutoffs treat 25 and up as overweight and 30 and up as obesity.)
| Category | BMI range |
|---|---|
| Underweight | below 18.5 |
| Normal | 18.5 - 22.9 |
| Overweight (pre-obesity) | 23.0 - 24.9 |
| Obesity class 1 | 25.0 - 29.9 |
| Obesity class 2 | 30.0 - 34.9 |
| Obesity class 3 (severe) | 35.0 or higher |
BMI alone cannot tell you where fat is distributed, so waist circumference is used to check abdominal (visceral) obesity. By Asian-Pacific criteria, abdominal obesity is a waist of 90 cm or more for men and 85 cm or more for women. Measure the waist at the midpoint between the lowest rib and the top of the hip bone, after breathing out.
| Sex | Abdominal obesity threshold |
|---|---|
| Male | waist 90 cm or more |
| Female | waist 85 cm or more |
Even with a normal BMI, a waist above the threshold can mean abdominal obesity, so it helps to look at both. If you also need to manage blood pressure, blood sugar and cholesterol, try the blood pressure, blood sugar and cholesterol tools.
Frequently asked questions (FAQ)
What is a normal BMI range?
Using Asian-Pacific cutoffs, a BMI of 18.5-22.9 is normal. Below 18.5 is underweight, 23-24.9 overweight (pre-obesity), 25-29.9 obesity class 1, 30-34.9 class 2, and 35 or higher class 3. (The WHO international cutoffs treat 25+ as overweight and 30+ as obesity.)
What is the waist threshold for abdominal obesity?
By Asian-Pacific criteria, abdominal obesity is a waist of 90 cm or more for men and 85 cm or more for women. Measure the waist at the midpoint between the lowest rib and the top of the hip bone, after breathing out.
Can BMI be normal but I still have abdominal obesity?
Yes. BMI uses only height and weight, so it does not reflect muscle mass or fat distribution. Even with a normal BMI, a waist above the threshold can indicate abdominal (visceral) obesity, so it helps to check both.
Do athletes get classified as obese by BMI?
People with high muscle mass can have a high BMI even with low body fat. BMI is useful as a population measure but does not capture individual body composition, so interpret it together with body fat percentage and waist circumference.
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Last updated: 2026-06-25