The BMI of Body Mass Index is a measurement based on a person's mass (measured in kilograms or pounds) and their height (measured in metres or inches). The BMI formula differs depending on whether you are using the metric or imperial system for your units of measure.
Below is the formula for calculating body mass index;
For metric measurements use your height in kilograms divided by your height in metres (i.e 1.75) squared. An example would be a man who weighs 80kg and is 1.75m tall. The equation is 80kg/(1.75*1.75) = 80/3.06 = 26.1 which is classed in the overweight category.
We will use the same man as above but convert the units. 80kg = 176lbs and 1.75m (175cm) equates to 68.9 inches. In this case we divide the mass (176lbs) by our height in inches squared. 176/(68.9*68.9) = 176/4747.21 which = 0.037. Then we multiply by 703 which gives us 26.1 also.
Your Weight in Kilograms (kg):
Your Height In Centimeters (cm):
Your Weight in Pounds (lbs):
Your Height In Inches:
Very severely underweight
less than 15
from 15.0 to 16.0
from 16.0 to 18.5
Normal (healthy weight)
from 18.5 to 25
from 25 to 30
Obese Class I (Moderately obese)
from 30 to 35
Obese Class II (Severely obese)
from 35 to 40