BMI Categories
< 18.5
Underweight
18.5 – 24.9
Normal
25 – 29.9
Overweight
30+
Obese
BMI is a general indicator. Consult a healthcare professional for personalized advice.
What is BMI?
BMI (Body Mass Index) is a number calculated from your height and weight. It's used as a screening tool to indicate whether you're underweight, normal weight, overweight, or obese. BMI does not measure body fat directly.
How is BMI calculated?
BMI is calculated by dividing your weight in kilograms by the square of your height in meters (kg/m²). For example: weight 70 kg, height 1.75 m gives BMI = 70 ÷ (1.75 × 1.75) ≈ 22.9.
You can use our calculator above with metric (centimeters and kilograms) or imperial (feet, inches, and pounds)—we do the conversion for you.
Frequently asked questions
- What is BMI?
- BMI (Body Mass Index) is a number calculated from your height and weight. It's used as a screening tool to indicate whether you're underweight, normal weight, overweight, or obese. BMI does not measure body fat directly.
- How is BMI calculated?
- BMI is calculated by dividing your weight in kilograms by the square of your height in meters (kg/m²). For example: weight 70 kg, height 1.75 m gives BMI = 70 ÷ (1.75 × 1.75) ≈ 22.9.
- What is a normal BMI?
- A normal or healthy BMI for adults is between 18.5 and 24.9. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is obese. BMI is a general indicator; consult a healthcare provider for personalized advice.
For more on BMI and health, see the CDC’s BMI information.