About the BMI Calculator
The BMI Calculator works out your Body Mass Index from your height and weight, then shows which category you fall into — underweight, normal, overweight or obese. It supports both metric and imperial units.
How to use the BMI Calculator
- Enter your height and weight.
- Pick metric (cm/kg) or imperial (ft/lb) units.
- See your BMI value and what category it falls into.
Frequently Asked Questions
How is BMI calculated?
BMI = weight (kg) divided by height (m) squared. For imperial units we convert automatically before applying the same formula.
What is a healthy BMI range?
For most adults a BMI between 18.5 and 24.9 is considered the healthy range. Below 18.5 is underweight and 25+ is overweight.
Is BMI accurate for everyone?
BMI is a useful general guide but does not distinguish muscle from fat, so athletes may read high. Treat it as one indicator, not a diagnosis.
Is this BMI Calculator free?
Yes, it is completely free, private and requires no sign-up — your numbers never leave your device.