Calculate your Body Mass Index in metric or imperial units and see which weight range you fall in.
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How to use the BMI Calculator
- Choose metric (cm / kg) or imperial (ft-in / lb).
- Enter your height and weight.
- Your BMI, category and healthy weight range for your height appear instantly.
About this tool
Body Mass Index (BMI) is a simple screening number that relates your weight to your height: BMI = weight (kg) ÷ height (m)². The World Health Organization uses these ranges for adults:
| BMI | Category |
|---|---|
| below 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight |
| 25 – 29.9 | Overweight |
| 30 and above | Obese |
BMI does not distinguish muscle from fat and is not designed for children, pregnant women or very muscular athletes. Treat it as a starting point, not a diagnosis.
Frequently asked questions
What is a healthy BMI?
For most adults, a BMI between 18.5 and 24.9 is considered a healthy range.
How do I calculate BMI with pounds and inches?
BMI = 703 × weight (lb) ÷ height (in)². This calculator does that conversion for you when you pick imperial units.
Is BMI accurate for athletes?
Not really. Muscle is denser than fat, so muscular people can have a high BMI while carrying very little fat. Waist circumference or body-fat percentage are better measures in that case.
Does BMI work for children?
Children and teens use age- and sex-specific BMI percentile charts instead of the fixed adult ranges. This calculator is intended for adults aged 18+.