Diet Pepsi vs Pure Leaf black iced tea: which has more caffeine?

Pure Leaf black iced tea has more caffeine than Diet Pepsi on both counts: 54mg per 18.5 oz bottle against 35mg per 12 oz can, and about 3mg 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.

Diet Pepsi vs Pure Leaf black iced tea: the numbers

Sources: Diet Pepsi's figure is verified in our Diet Pepsi caffeine guide against Caffeine Informer (source); Pure Leaf black iced tea's figure is verified in our Pure Leaf black iced tea guide against PepsiCo label data (source).

Which one should you pick?

Pick Diet Pepsi when you want the lighter dose or a slower ramp, and Pure Leaf black iced 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

• Diet Pepsi: the full caffeine guide
• Pure Leaf black iced tea: the full caffeine guide
• The verified caffeine database

FAQ

Does Diet Pepsi or Pure Leaf black iced tea have more caffeine? Pure Leaf black iced tea: 54mg per 18.5 oz bottle versus 35mg per 12 oz can for Diet Pepsi.

Which is stronger per ounce? Pure Leaf black iced tea, at about 2.9mg per fluid ounce versus 2.9mg for Diet Pepsi.