Eagle-eyed reader Brian was sitting back and enjoying an ice-cold Mountain Dew when he noticed that something seemed funny about the math on the Nutrition Facts label.

Per the label, the 20 oz. bottle contains 2.5 servings of 8 oz. each. For the 8 oz. serving, it lists the calorie total as 110 calories. But for the full 20 oz. bottle it says 290 calories. Problem is, 110 x 2.5 = 275, not 290.

So what’s going on? Are the Pepsi people that bad at math?

We went straight to a rep for the beverage behemoth who explained:

The discrepancy is due to FDA Rounding Rules. For products greater than 50 calories per serving the rule is that you must round to the nearest 10 calorie increment.

What has happened in the case of Mountain Dew is that the 8oz serving is somewhere between 110 and 114 calories, rounded down to the nearest 10 that means it is labeled as 110.

So if the company uses the high end of that 110-114 calorie count when it extrapolates for the whole bottle, that gives you around 285 calories. And regulations require that number be upped to 290.

Here is a link to the FDA’s guide for rounding nutrition info up and down.

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