The formula, and where the number sits
BMI is your weight divided by your height squared. In imperial units it is weight in pounds × 703, divided by height in inches squared. The formula and the WHO/CDC category bands are identical for men and women — there is no separate "men's BMI" equation.
WHO and CDC categories
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Healthy weight |
| 25.0 – 29.9 | Overweight |
| 30.0 – 34.9 | Obese (class I) |
| 35.0 and above | Obese (class II–III) |
Same bands for all adults. BMI is a screening tool, not a measure of body fat or fitness.
Why BMI misreads muscular men
Muscle weighs more than the same volume of fat, so a heavily trained man carries more weight at the same height. That inflates BMI even when body fat is low — studies suggest up to a quarter of men can be misclassified this way.
Two men can share a height and weight yet have very different health, because BMI cannot tell muscle from fat.
Waist size fills the gap BMI leaves
Because BMI ignores where weight sits, waist circumference is the practical companion measure for men. Belly (visceral) fat drives heart and diabetes risk more than total weight does.
- Under 94 cm (37 in). Low-risk range.
- 94 to 102 cm (37–40 in). Increased risk — worth acting on.
- Over 102 cm (40 in). Substantially increased risk, regardless of BMI.
Common questions
Is BMI calculated differently for men?
No. BMI is weight in kilograms divided by height in meters squared, the same formula and the same category bands for everyone. What differs for men is interpretation: more muscle can push the number up without extra body fat.
What is a healthy BMI for a man?
The WHO and CDC put the healthy range at 18.5 to 24.9. Below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above is obese. These bands are a screening guide, not a diagnosis.
Can I have a high BMI and still be healthy?
Yes. Muscle is denser than fat, so a lean, strength-trained man can read as overweight on BMI. If your waist is under 94 cm and you are active with good blood work, a high BMI likely reflects muscle rather than fat.
