Check your Body Mass Index (BMI) instantly. Supports both Metric (cm/kg) and Imperial (ft/lbs) units with accurate health categories.
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How to Interpret Your Results
Understanding Body Mass Index
The Body Mass Index (BMI) is a screening method used by healthcare providers to identify potential weight problems. While it is not a perfect diagnostic tool (it does not account for muscle mass or bone density), it is the global standard for initial health assessment.
Standard Categories (WHO)
- Underweight: BMI less than 18.5
- Normal weight: BMI between 18.5 and 24.9
- Overweight: BMI between 25 and 29.9
- Obese: BMI of 30 or greater
A Note on Muscle Mass
Athletes and bodybuilders may have a high BMI because muscle weighs more than fat. In these cases, a high BMI does not necessarily indicate poor health.
The Math Behind It
BMI is calculated differently depending on your unit system, though the underlying ratio remains the same:
$$ BMI_{metric} = \frac{\text{weight (kg)}}{\text{height (m)}^2} \qquad \text{vs} \qquad BMI_{imperial} = 703 \times \frac{\text{weight (lbs)}}{\text{height (in)}^2} $$
Where:
- Weight: Measured in kilograms (kg) or pounds (lbs).
- Height: Measured in meters (m) or inches (in).
- 703: The conversion factor used only for the Imperial formula.