Body Mass Index (BMI) Calculator
The Formula
The formula for calculating BMI is:
\[BMI = \frac{Weight (kg)}{(Height (m))^2}\]
Where:
- BMI: Body Mass Index
- Weight: The person's weight in kilograms (kg)
- Height: The person's height in meters (m)
BMI Categories
- Underweight: BMI < 18.5
- Normal weight: 18.5 ≤ BMI < 25
- Overweight: 25 ≤ BMI < 30
- Obese: BMI ≥ 30
Calculation Steps
- Measure weight in kilograms or pounds
- Measure height in centimeters or inches
- If weight is in pounds, convert to kilograms (1 lb = 0.453592 kg)
- If height is in inches, convert to centimeters (1 inch = 2.54 cm)
- Convert height from centimeters to meters (divide by 100)
- Square the height in meters
- Divide weight by the squared height
- The result is the BMI
Example Calculation
Let's calculate the BMI for a person weighing 70 kg and 170 cm tall:
\[BMI = \frac{70 kg}{(1.70 m)^2} = \frac{70}{2.89} = 24.22\]
This BMI of 24.22 falls within the "Normal weight" category.