PlanetToolbox
BMI Calculator
Calculate body mass index, BMI category, and estimated healthy weight range from metric or U.S. units.
BMI
23.1
Category
Healthy weight
Healthy range
59.9 to 80.7 kg
Unit mode
Metric
BMI inputs
Estimate body mass index
BMI result
- BMI
- 23.1
- Category
- Healthy weight
- Healthy weight range
- 59.9 to 80.7 kg
- Delta to range
- Within healthy range
Notes
Result actions
BMI formula, categories, and limits
BMI is a quick adult screening estimate based on height and weight. It is useful for rough categorization, but it does not replace medical evaluation.
BMI formula
Metric BMI is weight in kilograms divided by height in meters squared. U.S. BMI uses 703 x weight in pounds divided by height in inches squared.
Adult BMI categories
- Underweight: BMI below 18.5.
- Healthy weight: BMI from 18.5 to less than 25.
- Overweight: BMI from 25 to less than 30.
- Obesity: BMI of 30 or higher.
Healthy weight range
The estimated healthy weight range uses the same height with BMI endpoints from 18.5 to 24.9. It is a screening range, not a personal medical target.
Important limitations
- BMI does not directly measure body fat or lean mass.
- BMI can be less useful for athletes, pregnant users, children, teens, and some medical situations.
- Use BMI alongside waist measurements, body composition context, medical history, and professional guidance when health decisions matter.
BMI calculator notes
BMI is a screening estimate for adults. It does not diagnose health, body composition, pregnancy needs, athletic build, or medical risk.
Frequently asked questions
What does BMI measure?
BMI compares body weight with height to estimate a general weight category for adults. It is a screening metric, not a diagnosis.
Does BMI measure body fat directly?
No. BMI does not directly measure body fat, muscle mass, bone density, pregnancy needs, or individual medical risk.
Can athletes have a high BMI?
Yes. People with higher muscle mass can have a high BMI even when their body fat level is not high.
What should I use with BMI?
BMI is more useful when considered with waist measurements, body composition, activity level, medical history, and professional health guidance.
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