How to Calculate the Calories in Fat Grams

Many people are confused when it comes to figuring out how to calculate the number of calories in a gram of fat.  Whether you are trying to eat a low fat diet or just stay under 30% of your calories from fat, for example, this simple calculation is one that you should know how to do.

What may be confusing is that food labels show both calories from fat and fat grams at the same time.  In addition, many diet plans call for no more than a certain number fat grams in a day while others call for a particular number of fat calories per day.

Here is the fact you need to know.  There are 9 calories in 1 gram of fat.  Simple enough, so let’s put that to use in two examples.

Example 1

Suppose you want to limit your diet to 25% calories from fat per day and you are on a 2,000 calorie diet.  How would you figure out how many fat grams per day you can have?

First, you would multiply 2,000 by 25% to get 500.  In other words, you want to eat 500 calories from fat.  Since there is 1 gram of fat in every 9 calories, you would divide this 500 by 9 to get 55.55 grams.  So, you should shoot for about 55 grams of fat to be at your 25% target.

Example 2

Suppose you want to limit your diet to 40 grams of fat per day and you are on a 1600 calorie diet.  How would you figure out how many fat calories in a day you should have?

The only number in this example that matters for the calculation is the grams of fat.  Since you want to limit yourself to 40 grams of fat, you only need to multiply by 9 to get 360 calories.  So, you should shoot for around 360 calories from fat each day.

A Few Considerations

Watching out for your total fat grams or calories is a good idea, as too much can cause health issues.  Keep in mind, however, that fat is not a bad thing – too much fat is a bad thing.  Also, there are different kinds of fat.  Some are actually beneficial for you in moderation while others are best avoided or used sparingly.

Lessons Learned:

  • 1 gram of fat = 9 calories
  • to figure your target in calories from your total calories – multiply total calories times desired fat percentage
  • to figure your target in calories using only desired grams – multiply grams times 9
  • to figure your target in grams from your total calories – multiply total calories times desired fat percentage divided by 9

Leave a Reply

Your email address will not be published. Required fields are marked *