The BMI calculator chart uses a measurement of Body Mass Index. BMI doesn’t account for differences in muscle mass and excess fat, but is a useful guide. Two 5 ft 9in (175cms) people can weigh 210lbs (93kg), with one having a body fat percentage of 6% and the other 40% are in very different shape, yet this scale considers both obese.
Body Mass Index was never intended to measure whether you are overweight, although many people use it like this. Rather it was designed as a simple categorizing tool for statistical use. For instance as a way to talk about how many people are overweight in a particular country.
Muscle is much denser and heavier than fat. Meaning waist to hip ratio and body fat percentage are better indications of whether you are really overweight or not.
What These BMI figures Mean?
over 30 is considered obese
between 25 and 29.9 is considered overweight
between 18.5 and 24.9 is considered a healthy Body Mass Index
under 18.5 is consider underweight