How to Calculate BMI

BMI stands for Body Mass Index. It is a simple way to estimate whether your body weight is in a healthy range compared to your height.

People often use BMI as a quick screening tool. It does not measure body fat directly, but it helps give a general idea of weight status.

BMI formula

The standard BMI formula is:

BMI = weight (kg) / height (m)²

This means you divide your weight in kilograms by your height in meters squared.

Example calculation

If a person weighs 70 kg and is 1.75 meters tall:

BMI = 70 / (1.75 × 1.75) = 22.86

A BMI of 22.86 is usually considered within the normal weight range.

BMI categories

Below 18.5 — Underweight
18.5 to 24.9 — Normal weight
25 to 29.9 — Overweight
30 or higher — Obese

Why use an online BMI calculator

Calculating BMI manually is easy, but using an online calculator is faster and reduces mistakes. You only need to enter your weight and height to get the result instantly.

Use our free BMI calculator

Try our free BMI calculator to get your result in seconds.

Try BMI Calculator