Calculate adult BMI from metric or imperial measurements. BMI is a general screening estimate, not a diagnosis.
Calculate adult BMI from kg/cm or lb/in measurements, with standard adult categories and clear screening limitations.
BMI is weight divided by height squared. Toolmera calculates the same BMI whether you enter kilograms and centimeters or pounds and inches, then maps the result to the standard adult categories.
For adults, the categories are: underweight below 18.5, healthy weight from 18.5 to below 25, overweight from 25 to below 30, and obesity at 30 or above. Toolmera also shows obesity class 1, 2 or 3 when the BMI is 30 or higher.
BMI does not directly measure body fat, muscle mass, fat distribution, fitness or metabolic health. A muscular person can have a high BMI without having a high body-fat percentage, while an older adult with lower muscle mass can have a BMI that understates body fat.
That is why BMI is best treated as a broad screening measure rather than a standalone judgment about an individual’s health.
The fixed adult BMI categories are not the correct reference for children or teenagers, who use age- and sex-specific percentile approaches. Standard adult BMI categories are also not intended for pregnancy.
If BMI is being used for a health decision rather than general information, interpret it alongside other relevant health information with a qualified healthcare professional.
Open the tool and select the mode or options that match your task.
Provide the inputs required for the result.
Check the calculation, assumptions and supporting output shown by Toolmera.
Reference material used for this page:
Useful next steps in the same workflow.
Yes. Switch the unit selector to Imperial to enter weight in pounds and height in inches.
No. BMI is a weight-to-height ratio and does not directly measure body fat or muscle mass.
The standard adult healthy-weight range is 18.5 to below 25. BMI is a screening category, not an individual diagnosis.
No. The fixed adult categories shown here are not the appropriate reference for children, teenagers or pregnancy.