Practical checks before interpreting BMI
The short answer
Check the units, how height was entered, the formula and the rounding convention before comparing results. A change in a displayed number is not by itself a change in health. Keep the calculation separate from personal treatment or weight goals.
Check the units, how height was entered, the formula and the rounding convention before comparing results. A change in a displayed number is not by itself a change in health. Keep the calculation separate from personal treatment or weight goals.
A reproducible calculation
Imperial inputs are converted using 1 lb = 0.45359237 kg and 1 in = 2.54 cm. Five feet nine inches is 69 inches, not 5.9 feet.
150 lb = 68.0388555 kg
5 ft 9 in = 69 in = 175.26 cm = 1.7526 m
BMI = 68.0388555 / 1.7526² = 22.1509004 kg/m² → 22.2 kg/m²
Units are converted before calculation. Categories use the unrounded result; only the display is rounded. The shortcut multiplier 703 can differ slightly from exact conversion.
Body mass index (BMI) is weight in kilograms divided by height in metres squared. It is one screening measure, not a diagnosis or a direct measurement of body fat.
Adults 20+. For ages 2–19, use a validated BMI-for-age calculator. This tool shows adult ranges only.
BMI is one screening measure, not a diagnosis or a weight goal. It does not distinguish muscle from fat and is not suitable for pregnancy.
The standard adult BMI formula is the same for women and men. The same BMI does not establish the same body composition or personal health risk.
This explanation checks the method and arithmetic. It does not claim an independent medical review. Personal interpretation requires context and an appropriate healthcare professional.
Sources
Sources below are in English.