BMI Calculator
About the BMI Calculator
Body Mass Index (BMI) is a simple screening measure that uses your height and weight to estimate whether your body weight falls in a healthy range for your height.
Formula Used
How It Works
BMI is calculated by dividing your weight in kilograms by the square of your height in metres (BMI = weight / height²). The result is then compared against WHO weight categories.
Step by Step
- Convert your height from centimetres to metres (divide by 100).
- Square the height in metres.
- Divide your weight in kilograms by that squared height value.
Worked Example
Example: A person weighing 65 kg with a height of 170 cm (1.70 m):
BMI = 65 / (1.70 × 1.70) = 65 / 2.89 = 22.5, which falls in the Normal weight range.
Reference Table
| BMI Range | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 - 24.9 | Normal weight |
| 25.0 - 29.9 | Overweight |
| 30.0 and above | Obese |
Frequently Asked Questions
Is BMI accurate for everyone?
BMI is a useful general screening tool, but it does not directly measure body fat and may be less accurate for athletes, elderly people, or pregnant women.
What is a healthy BMI range?
According to WHO guidelines, a BMI between 18.5 and 24.9 is considered a healthy weight range for most adults.
Does BMI differ for men and women?
The BMI formula itself is the same for men and women, though body fat percentage at the same BMI can differ between sexes.