A standard Body Mass Index chart is available online at the American Cancer Society website, under the Normal Weight Ranges: Body Mass Index section. The chart is used by cross-referencing height with weight to determine BMI, notes the American Cancer Society.
BMI is one method that health care professionals use to determine whether a person is at a healthy weight, overweight or underweight, states the American Cancer Society. Although BMI gives a good general estimate of total body fat to determine if a person has a weight problem, it may not be accurate for everybody. For instance, body builders who have high muscle mass often have a high BMI, but they are not usually overweight.