BMI Calculator
BMI Calculator
Understand your weight-to-height ratio.
How it works
Body Mass Index relates weight to height. The adult reference categories are a screening convention, not a summary of a person’s health.
Using this calculator
Enter height and weight. Imperial measurements are converted to metric before calculation. The result is displayed to one decimal place; categories use the full value.
What to keep in mind
For adults age 20 and over. BMI cannot separate muscle, fat and bone or describe fat distribution. It is not suitable for interpreting pregnancy or a child’s growth.
Sources & further reading
CDC · Adult BMI categories ↗Frequently asked questions
What are the adult categories?
Below 18.5: underweight; 18.5 to below 25: healthy weight; 25 to below 30: overweight; 30 and above: obesity. These are screening labels.
Does BMI measure body fat?
No. Two people with the same BMI can have very different body composition.
Are my entries saved?
No. Calculator inputs remain in the current page and are cleared when you reload or leave. The tools do not upload your entries.
Why are results rounded?
The display is rounded for readability. Calculations use unrounded intermediate values. An estimate should not be interpreted as an exact measurement.