Determining the Percentage of Fat

• 1). Refer to the nutrition label on your food or beverage product to determine the amount of calories and fat calories that each serving contains.
  
  Calories are the first bold item on the label. Fat calories will be located on the same line to the immediate right of the total calorie count.
  
  Notate both the calories and fat calories from the product by writing them on your paper.
  
  
• 2). Set up a simple algebraic equation that will serve as the method to determine the percentage of fat in the product at hand.
  
  In the equation, two fractions will be used side by side. The first fraction (on the left) will contain the number of fat calories as the numerator (top number). The total number of calories in the product will be the denominator (bottom number).
  
  The fraction to the right will always feature an "X" as the numerator (top number), and "100" as the denominator (bottom number). An equals sign should go between the two fractions.
  
  Our example food will contain 300 calories and 165 calories from fat. Our fraction would then look like this:
  
  165 = X
  ___ ___
  300 100
  
  
• 3). The total percentage of fat in the food product at hand will be equal to "X" in this equation.
  
  To determine the value of "X," multiply the numerator (top number) of the fraction on the left with the denominator (bottom number) of the fraction on the right.
  
  In the case of our sample food, 100 x 165 = 165,000.
  
  
• 4). Next, divide the product of the last step (in this case, 165,000) by the denominator (bottom number) of the fraction on the left.
  
  In the case of our sample food, 165,000 / 300 = 550.0.
  
  
• 5). If the value of "X" is higher than 100, move the decimal to the left until the number reached is lower than 100. (For example, if X = 138.0, the decimal would then move over one space to make the number 13.80.)
  
  In this sample equation, X = 550, which after movement of the decimal, converts to 55.
  
  We now know that this food product derives 55% of its calories from fat.
  
  (If the value of "X" is less than 100, there is no need to move the decimal point to get an accuate fat calorie percentage.)