What Is Going On With The Diet Mountain Dew Calorie Count?

If Diet Mountain Dew Has Zero Calories Per Serving, How Does It Have 15 Calories For 3 Servings?

I was enjoying a big bottle of chilled Diet Mountain Dew and noticed that the zero-calorie beverage had 15 calories if I drank the whole thing.

How does 0 X 3 = 15? Not that 15 calories is a big deal, but what’s up with that?

So I asked the AI bots, and here is what they explained...

Diet Mountain Dew can list 0 calories per serving because of FDA rounding rules, which allow anything under 5 calories per serving to be rounded down, but the total calories for the entire container (e.g., 3 servings) must be listed accurately if it exceeds 5 calories, often resulting in 10-15 calories total for a bottle despite "zero" per serving.

The actual calorie count per serving is likely between 1 and 4.9, which rounds to zero, but when multiplied by 3 servings (e.g., in a 20-oz bottle), the total (3-14.7 calories) gets rounded to 10 or 15 for the whole container.