brewed black tea vs Diet Pepsi: which has more caffeine?

brewed black tea has more caffeine than Diet Pepsi on both counts: 47mg per 8 oz cup against 35mg per 12 oz can, and about 6mg per fluid ounce against 3. The serving sizes differ, so the table below shows both ways of counting.

These are different categories of drink, which changes how the caffeine arrives. Energy drinks and sodas list an exact number because caffeine is a measured additive; brewed drinks vary with the beans and the brew, so their figures are compiled averages. The numbers here are the standard published values for each.

brewed black tea vs Diet Pepsi: the numbers

Sources: brewed black tea's figure is verified in our brewed black tea caffeine guide against USDA FoodData Central (source); Diet Pepsi's figure is verified in our Diet Pepsi guide against Caffeine Informer (source).

Which one should you pick?

Pick Diet Pepsi when you want the lighter dose or a slower ramp, and brewed black tea when you actually need the bigger hit and know your tolerance. If you are stacking either with other caffeinated drinks through the day, run the math against the 400mg reference rather than guessing.

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.

Related reading

• brewed black tea: the full caffeine guide
• Diet Pepsi: the full caffeine guide
• The verified caffeine database
• Every drink compared: the comparisons index

FAQ

Does brewed black tea or Diet Pepsi have more caffeine? brewed black tea: 47mg per 8 oz cup versus 35mg per 12 oz can for Diet Pepsi.

Which is stronger per ounce? brewed black tea, at about 5.9mg per fluid ounce versus 2.9mg for Diet Pepsi.