BMI Calculator
Calculate Body Mass Index using metric or imperial units.
What is BMI?
Body Mass Index (BMI) is a simple screening measure that relates your weight to your height, calculated as weight in kilograms divided by height in metres squared. This calculator supports both metric and imperial units and classifies the result using the World Health Organization's standard adult BMI categories.
How to use it
- Choose metric or imperial units.
- Enter your weight and height.
- Click Calculate BMI to see your BMI value and category.
The standard adult categories are: below 18.5 is underweight, 18.5-24.9 is a normal weight range, 25-29.9 is overweight, and 30 or above is classified as obese. BMI is a widely used starting point for population health screening because it only requires two easy-to-measure numbers, but it does not directly measure body fat percentage, and it does not account for muscle mass, bone density, age, sex or body composition — a very muscular person can show a high BMI without carrying excess fat. This calculator is for general information only and is not a substitute for advice from a qualified healthcare professional.