BMI Calculator
Calculate your Body Mass Index from your height and weight, in metric or imperial units.
Your measurements
What is BMI?
Body Mass Index estimates whether your weight is healthy for your height, using the formula weight (kg) divided by height (m) squared. It's a quick screening tool, not a diagnosis.
BMI categories
Under 18.5 is considered underweight, 18.5–24.9 is normal weight, 25–29.9 is overweight, and 30 or above is classified as obesity, per World Health Organization guidelines.
Frequently asked questions
Is BMI accurate for everyone?
BMI doesn't account for muscle mass, bone density, or body composition, so it can be less accurate for athletes, older adults, or pregnant people. It's a general screening guide, not a diagnosis.
What's a healthy BMI?
18.5–24.9 is generally considered the healthy range for most adults, though individual health depends on many other factors too.