BMI Calculator
Calculate your Body Mass Index (BMI).
About the BMI Calculator
Calculate your Body Mass Index (BMI) free in seconds using either metric (kg, cm) or imperial (lb, in) units. Enter your height and weight and this BMI calculator instantly shows your score and weight category — underweight, normal, overweight, or obese. BMI is a quick screen for a healthy weight; pair it with our calorie calculator to plan your goals.
How to use the BMI Calculator
- 1Choose metric or imperial units.
- 2Enter your weight and height.
- 3Read your BMI and weight category.
Frequently asked questions
What is a healthy BMI?
A BMI of 18.5–24.9 is considered normal weight. Below 18.5 is underweight; 25–29.9 is overweight; 30+ is obese.
Is BMI accurate for everyone?
BMI is a useful general screen but doesn't account for muscle mass or body composition, so athletes may read high. Use it as a guide, not a diagnosis.
How do I calculate BMI manually?
Divide your weight in kilograms by your height in meters squared (kg/m²). In imperial units: weight in pounds ÷ height in inches² × 703.