Calculating BMI - What's your Body Mass Index?

Our accurate Body Mass Index Calculator is used to determine whether you are in a healthy weight range for your height. BMI is one type of tool to help health professionals assess the risk for chronic disease and it is also important to understand your other risk factors. Use our free accurate BMI calculator now.


Accurate BMI Calculator

Our BMI Calculator is simple method to work out what your Body Mass Index is. Body Mass Index is a rule of thumb calculation that helps medical professionals in quickly working out if someone is classed as underweight, normal weight, overweight, or obese.

Atlas Says: The BMI calculation is applicable more to medical and public health professionals seeing trends in large populations, rather than a tool for individuals to work out if they are classed as a 'healthy' body shape.

How do you calculate BMI?

The BMI (Body Mass Index) calculation is pretty simple. You divided the body mass (kg) by the square of the body height (m). The result is your BMI with the units of kg/m2, resulting from mass in kilograms and height in metres.

Metric BMI Formula

BMI = kg / m2
(mass in kg divided by height in metres squared)

Imperial BMI Formula

BMI = (lbs x 703) / in2
(mass in lbs mutiplied by 703 divided by height in inches squared)

What does BMI work out?

BMI helps to categories your body mass in to 4 commonly used ranges which are underweight: under 18.5, normal weight: 18.5 to 25, overweight: 25 to 30, obese: over 30.

Atlas Says: The BMI calculate has it's limitations, including, if you are tall or have a higher than average muscle mass.

What are the limitations of BMI?

There are many limitations of BMI that stem from the fact that BMI is not an accurate measurement of health or fitness on an individual level. These include height and muscle mass.

Height: The BMI calculation states that a taller person is just a scaled up normal person, however, taller people tend to have slighter frames on average.

Muscle Mass: The BMI calculation does not differentiate between muscle mass or fat mass. A lean bodybuilder would be considered obese under BMI measurements.