BMI Calculator
Enter your height and weight to get your Body Mass Index (BMI) and category instantly — metric or imperial, no signup. BMI is a fast screening number; below the calculator you'll find the standard ranges and, just as importantly, what BMI can't see.
What's your BMI?
Takes five seconds.
BMI is a screening number, not a diagnosis — it doesn't know your muscle mass. The app's onboarding asks what actually matters.
Type your height and weight to see your number.
BMI categories (World Health Organization)
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Healthy range |
| 25.0 – 29.9 | Overweight |
| 30.0 and above | Obese |
What BMI doesn't tell you
- It can't tell muscle from fat. A lean, muscular lifter and an unfit person can share a BMI of 27 — one is 'overweight' on paper, the other isn't.
- It ignores where fat sits. Waist circumference and body-fat percentage track health risk better than a single height-and-weight ratio.
- It wasn't built for individuals. BMI was designed to describe populations, not to diagnose one person.
- It says nothing about what to do next. A number is not a plan.
How BMI is calculated
BMI = weight (kg) ÷ height (m)². The calculator converts imperial units for you, so you can enter feet/inches and pounds instead.
Your BMI is a starting point, not a plan.
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