How much caffeine is in Diet Pepsi?

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Diet Pepsi has 35mg of caffeine per 12 oz can, per Caffeine Informer. That works out to about 2.9mg per fluid ounce, well under brewed coffee at 11.9mg per ounce. Against the two standards everyone actually knows, one 12 oz can equals about 0.4 cups of brewed coffee or 0.6 shots of espresso.

Diet Pepsi vs coffee and espresso

How the number behaves

Sodas list an exact caffeine number because caffeine is a measured additive: every 12 oz can of Diet Pepsi carries the same 35mg, unlike brewed coffee, where the beans, dose, and brew time move the figure around. That predictability is the one real advantage a can has over a cup: you always know exactly what you drank.

The mistake people make is treating it as caffeine-free because it is "just a soda." At 35mg per 12 oz can, it takes about 11 servings to reach the 400mg FDA reference, but every serving still counts toward the same daily total as your coffee does.

Where to find it

Check Diet Pepsi prices on Amazon

Compare it

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For context, the FDA cites 400mg of caffeine a day as an amount generally not associated with negative effects in healthy adults. Tolerance and health vary, so treat these numbers as information, not advice.

FAQ

How much caffeine is in Diet Pepsi? 35mg per 12 oz can, per Caffeine Informer. That is about 2.9mg per fluid ounce.

Is Diet Pepsi stronger than coffee? No. Diet Pepsi carries 35mg per 12 oz can versus 95mg in an 8 oz cup of brewed coffee, and per ounce it is 2.9mg versus 11.9mg.

How many servings of Diet Pepsi reach 400mg of caffeine? About 11.4 of the 12 oz can servings reach the 400mg daily amount the FDA cites for healthy adults.

Sources: the Diet Pepsi figure (35mg per 12 oz can) is Caffeine Informer (source). Brewed coffee (95mg per 8 oz) and espresso (63mg per 1 oz) reference values are from USDA FoodData Central (source).