Calories Minicourse

A Bite-Sized Course on Calories

Do I really have to count calories?
When it comes to optimizing your health, calories are key. Calories convey how much energy comes from the foods and drinks you consume. Knowing how many calories you need and how many calories you are getting empowers you to reach your goals.

Counting calories does not have to be hard. Food labels as well as online databases provide the number of calories that common foods contain. Apps can help you track the calories you take in every day.

How many calories do I need?
Your body needs a certain number of calories to operate every day. Exactly how many calories you need depends on a lot factors including your age, energy spent, gender, height, and weight. Your goals like gaining, losing, or maintaining weight also
shape your calorie needs.

For more than 100 years, the Harris-Benedict equation has helped people compute their calorie needs. The most up-to-date equation is listed below, along with the related data needed to complete it.1

BMR x activity level = calories needed to maintain weight

BMR stands for basal metabolic rate. Your BMR is the level of calories your body needs daily to operate when you are not performing any activity. To compute your BMR, use the formula below for your gender.1

Female: 655.1 + (4.35 x weight in pounds) + (4.7 x height in inches) – (4.7 x age in years) = BMR
Male: 66 + (6.2 x weight in pounds) + (12.7 x height in inches) – (6.76 x age in years) = BMR

Some people are more active than others, and thus, require more calories. Below are activity levels you can use to complete the Harris-Benedict equation.1

1.375 – lightly active (light exercise 1-3 days per week)
1.55 – moderately active (moderate exercise 3-5 days per week)
1.725 – very active (hard exercise 6-7 days per week)
1.9 – extra active (very hard exercise, training, or a physical job)

A 42-year-old female works at a computer Monday through Friday and takes brisk walks 4 days a week. She weighs 135 pounds and stands 5’8” tall. Her BMR is 1,365 calories, which was calculated as follows: 655.1 + (4.35 x 135) + (4.7 x 68) – (4.7 x 42). She needs to consume 2,116 calories a day (1,364 x 1.55) to stay at her current weight.

You can also use online calculators like the one found at

How do I track my calories?
You can easily track your calories using resources like those offered at

You can search the MyFitnessPal food database to find out how many calories are in certain foods and drinks.
Find out your food’s calories here

You can also see how many calories you burn doing different exercises.2
Find out your calories burned here