Body mass index (BMI) is a simple measure of body weight relative to height. Enter your details to see your BMI and category, using either metric or imperial units.
For most adults, the World Health Organization classifies BMI as follows:
| BMI Range | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal / Healthy weight |
| 25.0 – 29.9 | Overweight |
| 30.0 – 34.9 | Obesity (Class I) |
| 35.0 – 39.9 | Obesity (Class II) |
| 40.0 and above | Obesity (Class III / severe) |
The formula is the same worldwide, just with different units:
For example, a person who is 175 cm (1.75 m) tall and weighs 72 kg has a BMI of about 23.5, which is in the healthy range.
For an adult of average build, a healthy BMI (18.5–24.9) corresponds to a specific weight range for each height. This calculator shows that range automatically. Here's a quick reference for common heights:
| Height | Healthy Weight Range |
|---|---|
| 5'5" (165 cm) | ~52–69 kg / ~115–152 lb |
| 5'8" (173 cm) | ~57–76 kg / ~126–168 lb |
| 5'11" (180 cm) | ~60–81 kg / ~132–179 lb |
| 6'1" (185 cm) | ~64–86 kg / ~141–190 lb |
| 6'3" (191 cm) | ~68–91 kg / ~150–201 lb |
BMI has well-known blind spots. Athletes and people with high muscle mass can show an "overweight" BMI while being very healthy. Older adults may have a normal BMI but low muscle. Children use age- and sex-specific percentile charts, not adult categories. So treat your BMI as one useful number among many, not the final word on health.
For most adults, a BMI between 18.5 and 24.9 is considered a healthy range. But because BMI ignores muscle and build, it's best used alongside other health indicators rather than alone.
The adult BMI categories are the same for men and women. However, body composition differs, so a doctor may interpret the same BMI differently depending on the person.
No. For children and teens, BMI is compared to age- and sex-specific growth charts (percentiles), not the adult categories. Use a pediatric growth chart or ask a pediatrician.
No. This calculator is a general screening tool for educational purposes. For any health concern or decisions, please consult a qualified healthcare professional.