BMI Calculator
Calculate Body Mass Index in metric or imperial units with category.
Frequently asked questions
How is BMI calculated?
Body Mass Index equals your weight in kilograms divided by your height in meters squared, and the imperial version uses weight in pounds times 703 divided by height in inches squared.
What are the BMI categories?
A BMI under 18.5 is underweight, 18.5 to 24.9 is a normal range, 25 to 29.9 is overweight, and 30 or above is considered obese.
Can I use pounds and inches?
Yes. The tool supports both metric and imperial units, so you can enter kilograms and centimeters or pounds and feet and inches.
What is a healthy BMI?
A BMI between 18.5 and 24.9 is generally described as the normal or healthy range for most adults, though it is only a rough screening measure.
Is BMI accurate for everyone?
Not always. BMI does not distinguish muscle from fat, so very muscular people or certain body types may get a misleading category.
Does BMI apply to children?
Adult BMI categories do not apply to children and teens, who are assessed with age and sex specific percentile charts instead.
Is this a medical diagnosis?
No. BMI is a general screening estimate and not medical advice, so consult a health professional for a full assessment.
Is my height and weight kept private?
Yes. The calculation runs in your browser and your measurements are never uploaded or stored.