"Body Mass Index or BMI is a tool for indicating weight status in adults. It is a measure of weight for height. BMI correlates with body fat. The relation between fatness and BMI differs with age and gender. For example, women are more likely to have a higher percent of body fat than men for the same BMI. On average, older people may have more body fat than younger adults with the same BMI."
Find your own BMI by using the BMI Calculators.