BMI FAQ
Answers to common questions about adult BMI, formula, accuracy, and reference ranges.
Is BMI a measure of body fat?
No. BMI is based on height and weight only. It does not directly measure body-fat percentage or distinguish muscle from fat.
Can a muscular person have a high BMI?
Yes. More muscle can increase weight without implying the same amount of body fat as someone with a different body composition.
What does BMI 24.9 mean?
It is the upper edge of the commonly used standard adult reference category. BMI is not a complete indicator of health, and the cutoff is not a personal prescription.
Does this calculator work for children?
No. Children and teenagers are assessed using age- and sex-specific BMI-for-age growth charts. This site uses adult cutoffs only.
Does BMI change when I switch units?
It should not, apart from small differences caused by rounding inputs. The formula is unit-independent once measurements are converted correctly.
Why show a weight range?
It helps explain the mathematical relationship between height and the adult BMI 18.5–24.9 reference interval. It is not a recommended target for every person.
Is my data stored?
The BMI calculation is performed in your browser. This tool does not require an account. Read the privacy policy for information about third-party services and general site data.
What if my BMI concerns me?
Consult a qualified healthcare professional for interpretation alongside other measurements, health history, and your personal circumstances.