BMI Calculator

Body mass index (BMI) is a measure of body fat based on height and weight that applies to adult men and women.

  • Enter your weight and height.
  • Select “Calculate” and your BMI will appear below.

BMI Calculator


Your BMI is......

less than 18.5: Underweight
18.5 - 24.9:Normal weight
25 - 29.9:Overweight
30 - 34.9:Class I Obese
35 - 39.9:Class II Obese
40 upwards:Class III Obese

BMI Categories:

How do I calculate my BMI?

The BMI is a simple calculation using your height and weight. The formula is BMI = kg/m2 where kg is your weight in kilograms and m2  is your height in metres squared.

What is the correct BMI for my age?

For adults over the age of 20, the BMI is calculated the same way for men and women, but the results are interpreted differently since boys and girls differ in body composition. Body composition also changes with age.

Underweight = <18.5
Normal weight = 18.5–24.9
Overweight = 25–29.9
Obesity = BMI of 30 or greater

What is a healthy BMI for a woman?

According to the National Institutes of Health, a healthy body mass index (BMI) for women falls between 18.5 and 24.9. Use the chart below to determine your BMI and see where it falls on the weight classification scale. If you are pregnant or plan on becoming pregnant soon, you can calculate your recommended weight gain using your pre-pregnancy BMI.

BMI before pregnancy chart*

What Next? Take action towards better health: