BMI Calculator
Body Mass Index calculator — metric and imperial. Shows category instantly.
About BMI Calculator
The BMI Calculator works out Body Mass Index from height and weight. Choose metric or imperial units, enter your measurements, and the tool returns your BMI value along with the standard category it falls into, such as underweight, normal, overweight, or obese. The result updates as you change the inputs.
The calculation runs in your browser, so your measurements are never recorded or uploaded. BMI is a general screening figure and does not account for muscle mass or body composition, so treat it as a rough guide rather than a medical assessment.
Frequently asked questions
- How is BMI calculated?
- BMI divides weight in kilograms by height in meters squared; the tool applies the same formula after converting imperial units.
- What do the categories mean?
- They follow the common ranges where a BMI under 18.5 is underweight, 18.5 to 24.9 is normal, 25 to 29.9 is overweight, and 30 or above is obese.
- Is BMI accurate for everyone?
- BMI does not distinguish muscle from fat, so it can be misleading for athletes and is best used as a starting point.