Free BMI Calculator Online
This free BMI calculator online lets you calculate BMI using your height in centimeters and weight in kilograms. Enter your measurements and select Calculate BMI to get your body mass index score and a standard adult BMI category instantly. The calculator is designed for quick everyday use on desktop, tablet, and mobile browsers.
Calculate BMI From Height and Weight
To calculate BMI, the tool converts height from centimeters to meters and divides weight in kilograms by height in meters squared. The BMI formula is BMI = weight (kg) ÷ height (m)². For example, a person who weighs 80 kg and is 1.80 m tall has a BMI of about 24.7.
BMI Categories and BMI Chart
For adults, standard BMI categories are commonly grouped as underweight, healthy weight, overweight, and obesity. The ranges used by major public-health sources are: under 18.5 for underweight, 18.5 to under 25 for healthy weight, 25 to under 30 for overweight, and 30 or higher for obesity. BMI is a screening measure and should be considered with other health information rather than used by itself to diagnose a condition.
| BMI Range | Standard Adult Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 to 24.9 | Healthy weight |
| 25.0 to 29.9 | Overweight |
| 30.0 or higher | Obesity |
BMI Calculator for Adults
This tool is intended as a simple BMI calculator for adults using the standard height-and-weight BMI formula. BMI does not directly measure body fat and can be less informative for some people, including highly muscular individuals. Public-health guidance recommends considering BMI alongside other relevant health information.
Metric BMI Calculator for US and UK Users
If you are searching for a BMI calculator USA or BMI calculator UK, this metric version uses centimeters and kilograms, so it can be used regardless of location. The underlying BMI calculation is the same mathematical measure; only the units entered by the user differ.
Why Use This BMI Calculator?
- Free BMI calculator: Calculate your BMI without a mandatory account.
- Quick BMI check: Enter height and weight to get a result in seconds.
- Simple BMI formula: Uses weight in kilograms and height in meters.
- BMI categories: Shows a standard adult category with the calculated score.
- Mobile-friendly: Works in modern desktop, tablet, and mobile browsers.
- Privacy-minded: The calculation runs in the browser, so ordinary measurements are processed locally by the page.
Understanding Your BMI Result
Your BMI number is a screening measure, not a diagnosis. A BMI result can provide one useful piece of information about weight relative to height, but it does not distinguish muscle from fat and does not capture every aspect of health. If you have concerns about your weight, health, pregnancy, an eating disorder, or a medical condition, consider speaking with an appropriately qualified healthcare professional.