BMI is a measure of body fat based on height and weight. The formula is [your weight (in pounds) divided by your height (in inches)²] x 703.
But how can you possibly measure a person’s body fat based on their height and weight alone? The flaw with BMI – body mass index – is that it doesn’t differentiate between amounts of fat versus muscle.
As far as I was aware, BMI has always been used to measure adults – have you ever heard of children being measured? The fact is that children are growing and developing at different rates – so how could a child’s BMI be accurate?