- BMI below 18.5 is underweight
- BMI between 18.5 and 24.9 is normal weight
- BMI between 25 and 29.9 are slightly overweight
- BMI between 30 and more are obese
- BMI above 40 is extreme obesity
BMI (Body Mass Index) is an international standard for calculating obesity. BMI is inaccurate since it does not distinguish between the weight of muscle and fat, and not where the fat is on the body. BMI is also inaccurate in elderly people and those with low height.
BMI figures do not apply to children, pregnant women and athletes with large muscle mass.
Here is the formula used: (Source WHO :)
For men and women from 20 years and older:
BMI = weight in kg / (height in meters * height in meters)
There are calculators for children online, as here: (To be used with extreme caution)
Better health channel.