FESTIVAL PERKS WITH OUTSIDE+ 

Don’t miss Khruangbin, Lord Huron, and more at the Outside Festival.

GET TICKETS NOW

GIFT YOURSELF OUTSIDE+

Khruangbin and Lord Huron to headline 2025 Outside Festival.

BUY TICKETS

Ask the Nutritionist: Are Calorie Counts Accurate?

How accurate are the calorie counts on package labels?

Heading out the door? Read this article on the new Outside+ app available now on iOS devices for members! Download the app.

To be honest, the calories listed on a Nutrition Facts label are an estimate rather than a strict value — but they are pretty darn close.

A calorie is quantified as the amount of energy required to raise the temperature of 1 milliliter of water by 1 degree Celsius. Scientists place a single, whole food in a calorimeter — a device with a combustion chamber, a thermometer and a container of water — and burn it. The rise in water temperature helps determine the approximate number of calories in that food.

Most manufacturers use existing databases (rather than conducting zillions of mini Bunsen burner bonfires) to determine the number of calories in each ingredient in a product, which they then add together to help determine their nutrition facts. To calculate the calories of your own recipes, check out calorieking.com or the U.S. Department of Agriculture’s food nutrient profile database — FoodData Central — for your (pretty accurate) totals.

Popular on Oxygen Mag