How to Convert Grams to Calories

Converting Fat Grams to Calories

Look at the nutrition label. Most food labels will list how many grams of fat there are for each serving of that specific product. This is how you will calculate the calories.

Multiply the fat grams by nine. Every gram of fat contains nine calories. To figure out how many calories there are in the fat content, simply multiple the fat grams by nine. For example, if there are ten grams of fat, you would multiple ten grams of fat by nine calories, for a total of 90 calories. This is how many calories there are in the fat grams.

Calculate how many calories there are in the entire product. To figure out how many total calories there are in the fat content of a product, multiply the original number you received before, by the amount of servings there are on the label. If a label states there are three servings, you would then multiply 90 by three, for a total of 270 calories.

Converting Grams of Carbohydrates and Proteins to Calories

Know that a carbohydrate is an organic compound. Carbohydrates are made of carbon, hydrogen, and oxygen. They always contain calories (4 per gram), but calories do not automatically mean there are carbohydrates, because calories are in other macro-nutrients.

Check the nutrition label. You will see how many grams of carbohydrates there are per serving. Carbohydrates have four calories per gram. Multiply the number of carbohydrates by four to figure out how many calories there are. For example, if a product had nine grams of carbohydrates, you would use the equation (9 x 4) to get a total of 36 calories. You would use four as your multiplier because there are four calories in every one gram of carbohydrate.

Find out the number of calories that come from protein. Proteins are also listed in grams on food labels. Just like carbohydrates, protein carries four calories per gram. Again, multiply the number of protein grams by four to receive the number of calories.

Understanding Grams vs. Calories

Realize the difference between a gram and a calorie. A gram is a metric unit of weight that is equal to one thousandth of a kilogram. A calorie is a unit of energy that people receive from food. One pound of body fat is equal to about 3500 calories. A gram and a calorie are different units of measure that can't be converted into one another.

Find out for which energy source you want to measure the calories. The quantity of calories per gram of food is dependent upon its ratio of macro-nutrients. The human body can derive energy (employ calories) from three main macro-nutrients: carbohydrates, fats, and proteins. You can't weigh food and convert the grams into calories. You have to know how many calories there are in a specific type of macro-nutrient gram to calculate the total calories in it.

Multiply the number of grams by the conversion number. Look on the label of the food your want to calculate the calories for. Each nutrient will be listed in grams. Once you find the one you are looking for, you can multiply that number by the number of calories that specific nutrient has in each gram.