They might look the same and, in most cases, taste the same. But when it comes to the number of calories in a bowl of popcorn, the numbers can vary widely, depending on the type of popcorn.
According to Daily Plate, a serving size of Orville Redenbacher, Act II and Pop Secret microwave popcorn is four cups of popped corn. The calorie total for this amount of regular popcorn is between 120 and 140 calories, with three servings per bag for a total between 360 and 420 calories. Butter and Kettle Corn flavors are generally in the 140 calorie range, with plain popcorn around 120 calories.
Light popcorn, regular and butter flavors, are generally 100 calories per serving, also with three servings per bag. The major brands also offer mini-bag packages of light popcorn that contain 100 calories.
94 Percent Fat Free Popcorn
Bags of 94 percent fat free popcorn contain between 55 and 60 calories per serving, with two servings per bag.