BMI gives you an idea of whether you’re 'underweight', a 'healthy' weight, 'overweight', or 'obese' for your height. BMI is one type of tool to help health professionals assess the risk for chronic disease.
It compares your weight to your height, and is calculated by dividing your weight (in kilograms) by your height (in metres squared).
There is a difference in calculating the BMI of adults from that of children and adolescents. Unlike adults', the children's BMI should be compared with the percentile for age and sex.
This app offers you a chance to calculate BMI for both sex and all age groups.