How this BMI Calculator Works
Body Mass Index (BMI) is a simple screening tool used to identify potential weight problems for adults. It calculates a value based on your height and weight to categorize whether you are underweight, at a healthy weight, overweight, or obese.
The Metric Formula
BMI = weight (kg) / [height (m)]²
The Imperial Formula
BMI = 703 × weight (lb) / [height (in)]²
BMI Categories
Standard weight status categories associated with BMI ranges for adults:
- Underweight: BMI below 18.5
- Normal weight: BMI between 18.5 and 24.9
- Overweight: BMI between 25 and 29.9
- Obesity: BMI of 30 or greater
Step-by-Step Instructions
- Select Units: Choose between Metric (kilograms/centimeters) or Imperial (pounds/inches).
- Enter Weight: Input your current weight in the selected unit.
- Enter Height: Input your height. Note that for Metric, use centimeters (e.g., 175), and for Imperial, use total inches (e.g., 70 inches for 5'10").
- View Result: The calculator instantly updates your BMI number, category, and positions the needle on the visual gauge.