How BMI is calculated
BMI is your weight in kilograms divided by the square of your height in metres. The calculator converts feet and inches to metres for you (1 inch = 2.54 cm).
BMI = weight (kg) ÷ height (m)²
Example
A person 5 feet 8 inches tall (1.727 m) weighing 72 kg has a BMI of 72 ÷ 1.727² = 24.1.
WHO and Asian BMI categories
| Category | WHO | Asian cut-offs |
|---|---|---|
| Underweight | below 18.5 | below 18.5 |
| Healthy | 18.5 – 24.9 | 18.5 – 22.9 |
| Overweight | 25 – 29.9 | 23 – 27.4 |
| Obese | 30 and above | 27.5 and above |
Research shows that South Asians tend to face health risks such as diabetes and heart disease at lower BMI levels than Europeans. That is why lower "Asian" cut-offs are often used in Pakistan and India. Both are shown so you can compare.
Limits of BMI
BMI does not tell muscle from fat, so very muscular people can score high. It is also not used for children, teenagers or pregnant women. Treat it as a starting point and speak to a doctor for advice about your own health.
Frequently asked questions
What is a normal BMI?
The WHO range is 18.5 to 24.9. Many doctors in South Asia use 18.5 to 22.9 as the healthy range.
How do I calculate BMI with height in feet?
Choose 'Feet & inches', enter your feet and inches, and your weight in kg. The calculator converts it for you.
Is BMI accurate for everyone?
No. It is a general screening tool for adults and does not account for muscle mass, age or body shape.