How to Count Calories in Food

Feeling healthy and feeling good about yourself is not a luxury – it’s an absolute necessity.

How to Count Calories in Food


Counting calories has almost become a lost ‘art’ since the birth of electronic gadgets, which enable you to look up food facts in a snap. However, learning how to count calories makes it easier to lose weight or even maintain your weight. You can avoid high-calorie foods, swapping them with lower-calorie choices instead, foods that facilitate weight loss while satisfying your nutritional requirements.

It’s essential that you know the definition of a ‘calorie’ before you begin counting them. Calories are a measure of the energy content of a food or the amount of energy needed to raise the temperature of 1 gram of water by 1⁰ Celsius. The correct word is actually ‘kilocalorie’ which has been abbreviated simply to ‘calorie’. A kilocalorie equals 1000 calories. For example, fat has 9 calories per gram, that is 9 kilocalories per gram. This means that a gram of fat has enough energy to raise the temperature of 1000 grams of water 9⁰ Celsius.

First you must calculate how many calories you need to maintain, lose or gain weight (depending upon your goals). Use the Harris Benedict or Mifflin St. Jeor equation and add the appropriate physical activity factor (PAL) to that number. The result of your initial calculation is your target for weight maintenance. To lose 1 lb per week, you will need to create a calorie deficit of 500 calories per day or 3,500 in one week. On every nutrition facts panel you will find (at the bottom) a reminder of how many calories are in a gram of each of the macronutrients: fat, protein and carbohydrate. Fat offers 9 calories per gram and protein and carbohydrates offer 4 calories each per gram. Alcohol provides 7 calories per gram.

Most foods contain a mixture of the three macronutrients (carbs, fat and protein). Correctly reading and interpreting a nutrition fact panel/label is essential to successful calorie counting. Having a few basic tools at your disposal makes calorie counting easier:

  • A food scale and measuring cups/spoons
  • A list of foods and caloric values
  • A calculator
  • A notebook or ‘journal’ to record the foods you eat

It’s always easiest to count calories when you stick to exact serving sizes, or ‘one’ serving as specified on a nutrition facts panel. However, if you eat more or less than one serving, the number of calories will vary. Even so, you can still accurately count the amount of calories you’ve consumed. A standard serving of whole almonds is 1 oz. or about 23 whole kernels. This amount provides 164 calories. Next to the serving size the weight of that serving size will be listed (28 grams to 1 oz.). If you grab a handful of almonds, it will likely not be exactly 1 oz. Weigh that handful on your food scale. If it weights 40 grams, you need to calculate the number of calories in that amount.

40 grams x (164 calories ÷ 28 grams) = approximately 234 calories

Perhaps you want to limit your almond snack to 150 calories. Simply modify the equation:

150 calories x (28 grams ÷ 164 calories) = about 25.6 grams (weigh out 25.6 grams of almonds on your food scale)

The first week or two of calorie counting is the toughest because you have to look up the caloric content of each food (if a label is not available). Measuring cups and spoons are essential for accuracy. Measure out your foods until you know what one serving looks like in your own dish.

Keep a detailed food log in a notebook or journal. Do not rely on your memory! Be sure to note the food item, portion size and calories. You can do this on your computer with a spreadsheet and set it to add up certain rows for meal and/or daily calorie totals.

Luckily there are free websites that enable you to look up food values and even track your daily intake to compare with your goals. The U.S. Department of Agriculture National Nutritional Database is one such resource. You can also set up a profile and track your daily intake using the MyPyramid Tracker.

Keep in mind that accurately counting calories can be time consuming and tedious. Nearly 9 out of 10 Americans misjudge the amount of calories they consume. Remember, though calories matters for weight management, adhering to a specific calorie count does not mean that your diet is healthy, well balanced and adequate.


  • Drummond, K.E. & Brefer, L.M.: Nutrition for Foodservice & Culinary Professionals, 7th ed. John Wiley & Sons, Inc., New York, New York, 2010.
  • The Mayo Clinic. “Counting Calories: Get Back to Weight Loss Basics.”
  • American Association of Retired Persons (AARP): Fat to Fit – How many calories do you need? May 2011.


Leave a Reply

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