The body mass index (BMI), or Quetelet index, is a statistical measurement which compares a person’s weight and height.

 BMI is an alternative method to assess an individual’s body fatness and corresponding health.

BMI was roughly invented between 1830 and 1850 by the Belgian polymath Adolphe Quetelet during the course of developing "social physics". It became popular in the 1950’s and 1960’s due to an increase in obesity.

The following are the most widely accepted methods for calculating your Body Mass Index (BMI).

• BMI Formulas
• BMI Charts
• BMI Calculator
• Bioeletrical Impedance Analyzer

 Formula: weight (kg) / [height (m)]²

With the metric system, the formula for BMI is weight in kilograms divided by height in meters squared. Since height is commonly measured in centimeters, divide height in centimeters by 100 to obtain height in meters.

Example: Weight = 68 kg, Height = 165 cm (1.65 m)
Calculation: 68 ÷ (1.65)² = 24.98

Below 18.5

18.5 - 24.9

25.0 - 29.9

30.0 and Above

This method measures electrical signals as they pass through the fat, lean mass, and water in the body. They can be handheld or a scale.

An undetectably low voltage is sent into the body usually via hands or feet. Since fat is a very poor conductor of electricity, a lot of fat will impede the current more so than a lot of lean tissue. By measuring the resistance to the current, the machine estimates the percent body fat.

This machine also shows results for BMI based on the information you entered before the sending of low voltage.

BMI is not the most accurate method of body composition. The following is a list of discrepancies with BMI.

• At the same BMI, women tend to have more body fat than men.
• At the same BMI, older people, on average, tend to have more body fat than younger adults.
• Highly trained athletes may have a high BMI because of increased muscularity rather than increased body fatness.