BMI Calculator for Adults
Calculate adult body mass index from metric or US measurements and understand what the number can and cannot show.
Calculate your estimate
What this calculator estimates
Body mass index compares weight with height. It is a screening measure, not a diagnosis and not a direct measurement of body fat, muscle mass, health or fitness.
The formula
BMI equals weight in kilograms divided by height in meters squared. The calculator also accepts pounds and inches and converts them before applying the same formula.
Interpret it carefully
Population categories can be useful for screening, but an individual result needs context. Muscularity, age, pregnancy, body composition and other factors can affect how informative BMI is for one person.
Look beyond one number
Waist measurements, blood pressure, laboratory results, fitness, sleep, eating patterns and clinical history may add context. Only a qualified professional can assess those factors together.
Use trends constructively
If you track BMI, focus on gradual changes and the habits that produced them. Avoid using a category as a judgment about appearance, worth or discipline.
Frequently asked questions
Is this result exact?
No. It is a transparent planning estimate based on averages. Validate it against real trends and how you feel.
How often should I recalculate?
Recalculate after a meaningful change in weight, activity or goal. Avoid changing the plan because of one day of scale movement.
Sources and further reading
DietSuccess links to primary public-health resources so readers can check the underlying guidance. External resources may be updated after this page is published.
Turn estimates into a daily routine
Track meals, activity, weight trends and progress in one private dashboard.