What Is BMI?
Body Mass Index (BMI) is a screening measure that compares your weight with your height and helps identify a general adult weight category.
How Is BMI Calculated?
BMI is calculated using BMI = weight (kg) ÷ height² (m²). This calculator automatically converts supported US and metric measurements.
BMI Categories for Adults
| BMI Range | Weight Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Healthy Weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and above | Obesity |
BMI Calculator in US and Metric Units
Use US Units for feet, inches, and pounds, or Metric Units for centimeters and kilograms. Other Units also supports meters, stone, and pounds.
BMI for Men and Women
Standard adult BMI category cutoffs are generally the same for men and women, although BMI does not directly measure body fat or muscle mass.
BMI for Children and Teenagers
For ages 2–19, BMI is interpreted using age- and sex-specific BMI-for-age percentiles rather than fixed adult BMI categories.
Is BMI Accurate?
BMI is useful for screening, but it does not directly measure body fat and is not a diagnosis. Your result should be considered together with other health information.
Frequently Asked Questions About BMI
How do I calculate my BMI?
Divide your weight in kilograms by the square of your height in meters, or use the calculator above for an automatic result.
What is a normal BMI?
For most adults, a BMI from 18.5 to 24.9 is commonly classified as the healthy-weight range.
Can I calculate BMI using pounds and feet?
Yes. Select US Units and enter your height in feet and inches and your weight in pounds.
Does BMI tell me my body fat percentage?
No. BMI is based on height and weight and does not directly measure body fat percentage.
Health information: This BMI calculator is intended for general educational and screening purposes. It is not a substitute for professional medical advice, diagnosis, or treatment.