Health Numbers
Calculate your Body Mass Index instantly. Understand what it means — and its limitations — for men.
The World Health Organization defines BMI ranges for adults as follows:
| BMI Range | Category | Risk Level |
|---|---|---|
| 0 – 18.5 | Underweight | Low |
| 18.5 – 25 | Normal Weight | Minimal |
| 25 – 30 | Overweight | Moderate |
| 30 – 35 | Obese (Class 1) | High |
| 35 – 40 | Obese (Class 2) | Very High |
| ≥ 40 | Morbidly Obese | Extreme |
Body Mass Index (BMI) is a numerical value calculated from your height and weight. It is widely used as a screening tool to categorise adults into weight groups that may correlate with health risk. BMI was developed by Belgian statistician Adolphe Quetelet in the 19th century and adopted broadly by health organisations in the 1970s.
The formula is straightforward: BMI = weight (kg) ÷ height² (m²). In imperial units: BMI = 703 × weight (lbs) ÷ height² (inches²).
While body mass index is a well-known index for measuring body composition, it is not necessarily the best measure for men. It does not take into account an individual's body type or composition — the ratio of muscle mass to fat mass. This causes the ratio to be inaccurate for men with a higher percentage of muscle mass and a lower percentage of body fat.
For example, a man that loses 10 lbs of fat and gains 10 lbs of muscle will have the exact same BMI but will likely be much healthier. Therefore, BMI may not be an accurate predictor of common health problems such as diabetes, high blood pressure, and heart disease in certain individuals.
External Resource: NIH: Body Mass Index