Medically reviewed by Suzanne Fisher, RDCalculating your body mass index (BMI) involves using a simple formula with your weight (in pounds or kilograms) and height (in inches or meters). BMI is used ...

Use this calculator to determine whether a child is at a healthy weight for his/her height, age and sex. The BMI-percentile-for-age calculator automatically adjusts for differences in height, age and ...

The situation is more complex in children, where the BMI threshold of obesity varies with age and sex. The charts below show how the BMI obesity threshold changes with age for boys and girls.

BMI charts are calculated for adults only (separate charts are available for children’s weight and heights). Inaccuracies can also occur if you're an athlete or very muscular as this can give ...