Here are the BMI standards as set by the World Heath Organization:
| BMI | Category |
|---|---|
| < 18.5 | Underweight |
| 18.5 - 25 | Healthy Weight |
| 25 - 30 | Overweight |
| > 30 | Obese |
In the United States, the average BMI for adults is 28.8.
Metric
BMI = kg / m2
Imperial
BMI = (lbs * 0.45359237) / (inches * 0.0254)2
Simplified
BMI = 703 * lbs / inches2
Body Mass Index is a very simplistic method of determining whether a person is overweight. It does not taken into account a person's frame, gender, or muscularity. Furthermore, at least one study has suggested that slightly overweight people may live longer than people in the "normal" range.
Nevertheless, BMI is highly correlated with body fat % and is a decent enough yardstick of a healthy weight.