Pepsi, Diet Pepsi and Pepsi Zero Sugar
A 12 fl oz can of Pepsi carries 38 mg of caffeine, by PepsiCo’s own product facts. Pepsi Zero Sugar carries the same 38 mg per can, and Diet Pepsi slightly less, 35 mg per 12 oz serving. The three sit within a few milligrams of each other. That is not true of Coca-Cola’s range, where Diet Coke carries a third more caffeine than the original.
Against its rival, Pepsi carries 4 mg more than Coca-Cola (34 mg) and 8 mg less than Diet Coke (46 mg). Mountain Dew, also a PepsiCo drink, carries more than either at 54 mg. USDA’s figure for regular cola, about 33 mg a can, puts Pepsi slightly above the category average.
Bottles and multi-serving labels
PepsiCo lists nutrition per container, and larger bottles are often labelled in 12 oz servings. The 24 oz Diet Pepsi bottle, for example, is labelled as two 12 oz servings of 35 mg each, 71 mg for the whole bottle. For Pepsi and Pepsi Zero Sugar the arithmetic is roughly 3 mg of caffeine per fluid ounce, so a bottle’s total is easy to estimate from its size once you know that rate.
Where it fits in a day
At 38 mg a can, ten cans stay under the 400 mg daily figure the FDA cites for healthy adults (380 mg), and the eleventh goes over. A can is about 40% of an 8 oz cup of drip coffee at USDA’s reference strength (95 mg). In pregnancy, five cans, 190 mg, fit under the 200 mg daily ceiling ACOG uses.
For anyone avoiding caffeine, PepsiCo sells Caffeine Free Pepsi and Caffeine Free Diet Pepsi. For young children the FDA notes that the Dietary Guidelines for Americans say drinks containing caffeine should be avoided under the age of two.