BMI Calculator
Enter your weight and height to see your body mass index, the category and a healthy weight range.
Quick answer: BMI is weight in kilograms divided by height in meters squared. For example 160 pounds at 5 feet 8 inches is a BMI of 24.3, in the healthy range of 18.5 to 24.9. This is general information for adults, not medical advice.
How to use it
- Choose US units (pounds, feet and inches) or metric (kilograms and centimeters).
- Type your weight and height.
- Your BMI and its category appear, with the weight range that falls in the healthy BMI band for your height.
The formula
Metric: BMI = kg ÷ m². US: BMI = 703 × pounds ÷ inches². A person who weighs 70 kg and is 1.75 m tall has a BMI of 70 ÷ 3.0625 = 22.9.
General information only, not medical advice. Ask a doctor or a dietitian about your own health.
Adult BMI categories (WHO)
| BMI | Category |
|---|---|
| Under 18.5 | Underweight |
| 18.5 to 24.9 | Healthy weight |
| 25.0 to 29.9 | Overweight |
| 30.0 to 34.9 | Obesity, class 1 |
| 35.0 to 39.9 | Obesity, class 2 |
| 40.0 and over | Obesity, class 3 |
Limits of BMI
BMI is a screening number, not a diagnosis. It does not tell fat from muscle, so a muscular athlete can have a high BMI and be healthy. It can also miss health risks in older adults, and the cut-off points may differ for some ethnic groups. It is not meant for children and teenagers, who are assessed with growth charts, or for pregnant women. Waist size, fitness, diet and blood tests matter too.
What people use it for
- A quick health check
- Setting a weight goal with your doctor
- Understanding a doctor's number
- Curiosity
Questions
How do I calculate BMI?
Divide weight in kilograms by height in meters squared, or multiply pounds by 703 and divide by inches squared.
What is a healthy BMI?
18.5 to 24.9 for most adults.
Is BMI accurate?
It is a rough guide. It does not measure body fat directly.
Does BMI work for children?
No. Children and teens use age and sex based growth charts.
Is my data saved?
No. The calculation runs in your browser.
Is it free?
Yes. No sign-up, no install and no limit.
Is anything saved or sent?
No. Everything runs in your browser. Only your own best score, where a page shows one, is kept on your device.
Last updated 2026-10-24. Free to use, no sign-up. Made by ficklestudio26.