Pepsi Zero Sugar vs Red Bull: which has more caffeine?

Red Bull has more caffeine than Pepsi Zero Sugar on both counts: 80mg per 8.4 oz can against 69mg per 12 oz can, and about 10mg per fluid ounce against 6. 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.

Pepsi Zero Sugar vs Red Bull: the numbers

Sources: Pepsi Zero Sugar's figure is verified in our Pepsi Zero Sugar caffeine guide against PepsiCo product facts (source); Red Bull's figure is verified in our Red Bull guide against Red Bull label / Caffeine Informer (source).

Which one should you pick?

Pick Pepsi Zero Sugar when you want the lighter dose or a slower ramp, and Red Bull 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

• Pepsi Zero Sugar: the full caffeine guide
• Red Bull: the full caffeine guide
• The verified caffeine database
• Every drink compared: the comparisons index
• Compare any two of 120+ drinks

FAQ

Does Pepsi Zero Sugar or Red Bull have more caffeine? Red Bull: 80mg per 8.4 oz can versus 69mg per 12 oz can for Pepsi Zero Sugar.

Which is stronger per ounce? Red Bull, at about 9.5mg per fluid ounce versus 5.8mg for Pepsi Zero Sugar.