What is the BMI Calculator?

Body Mass Index (BMI) is a quick screening measure that relates your weight to your height to suggest whether you fall in the underweight, healthy, overweight, or obese range. This BMI calculator accepts both metric (kilograms and centimetres) and imperial (pounds and feet/inches) units, computes your BMI using the standard formula, and shows which category it falls into along with the healthy range for your height. It is a useful starting point for thinking about weight, but it has real limitations: BMI does not distinguish muscle from fat, so very muscular people can read as overweight, and it does not account for age, sex, or where fat is distributed. Treat the result as one data point, not a diagnosis, and consult a healthcare professional for personalized advice. Your measurements are processed in your browser and never stored or shared.

How to use the BMI Calculator

1. Choose metric or imperial units.
2. Enter your height.
3. Enter your weight.
4. Read your BMI value and the category it falls into.

Common use cases

• Quickly screening weight status against height
• Tracking BMI changes over a weight-management program
• Getting a starting point before a doctor consultation

Frequently asked questions

What is a healthy BMI range?

For most adults, a BMI between 18.5 and 24.9 is considered healthy. Below 18.5 is underweight, 25-29.9 is overweight, and 30 or above is obese.

Is BMI accurate for athletes?

Not always. BMI cannot tell muscle from fat, so muscular individuals may register as overweight despite low body fat. Use it alongside other measures.

What BMI formula does this use?

It uses the standard formula: weight in kilograms divided by height in metres squared. Imperial inputs are converted automatically.