Use the free Body Mass Index (BMI) Calculator or BMI Calculator (somtimes called the Quetelet Index Calculator) to measure your Body Mass Index or BMI. The BMI is your body composition index which is a measure based on height and weight that applies to both adult men and women.

The Body Mass Index used in the calculator below, is calculated from an individual's weight divided by the square of the height. The U.S. National Heart, Lung and Blood Institute uses the BMI to classify obesity.

For more free information about the BMI, the BMI Calculator, ideal weight and the relationship with body fat see the Body Mass Index (BMI) FAQ.

To calculate your BMI enter your weight and height in the calculator below. Please note this calculator is only a guide and does not take into account body frame or large muscle volume for example in athletes and body builders. Alternatively you can calculate your body fat from BMI or see our list of body fat calculators based on anatomical measures and skinfold values.

Body Mass Index (BMI) Calculator

Enter your body weight
  in one of the three rows
stone   pounds  
Enter your height
  in one of the three rows
feet   inches   
 Calculated BMI number =   
BMI Classification =   

The BMI values correspond to the following body analysis:

  • Underweight, BMI = <18.5
  • Normal weight, BMI = 18.5-24.9
  • Overweight, BMI = 25-29.9
  • Obesity, BMI = 30 or greater