How this calculation works
BMI compares weight with height squared. It is a screening measure, not a measurement of body fat or a diagnosis. The category uses the unrounded BMI, while the displayed number is rounded to one decimal. The accompanying weight interval simply reverses the equation at BMI 18.5 and 24.9; it is not a personal weight-loss target.
Worked example
This example uses illustrative inputs. Your current result is shown above.
At 70 kg and 175 cm, height is 1.75 m. BMI = 70 ÷ (1.75 × 1.75) = 22.857…, displayed as 22.9. This falls in the adult healthy-range screening category. The reference weights are 18.5 × 3.0625 = 56.7 kg and 24.9 × 3.0625 = 76.3 kg after rounding.
Assumptions and limits
- The adult categories are below 18.5, 18.5 to below 25, 25 to below 30, and 30 or above. Children and teenagers need age- and sex-specific assessment.
- BMI does not distinguish muscle, fat and bone or account for pregnancy. Risk can differ with ethnicity and medical history even at the same BMI.
- The reference interval ends at BMI 24.9 for display; the category boundary itself is below 25. Category selection happens before rounding.
Questions people ask
Can a muscular person have a high BMI without excess body fat?
Yes. Weight contributes to BMI regardless of whether it is muscle or fat. A clinician can interpret it alongside waist size, medical history and other measurements.
Why might 25.0 still appear beside the lower category?
A value just below 25 can round to 25.0. The category uses the more precise value, not the rounded display.
Is the reference weight interval a recommended goal?
No. It is the weight corresponding to two BMI values at your entered height. It cannot determine a safe or appropriate individual goal.