Pepsi Zero Sugar has more caffeine than Coca-Cola Classic: 69mg vs 34mg in the same 12 oz can. That is a 35mg gap, and since the cans match, the per-serving number is the whole story.
Pepsi Zero Sugar vs Coca-Cola Classic: the numbers
| Pepsi Zero Sugar | Coca-Cola Classic | |
|---|---|---|
| Caffeine per serving | 69mg per 12 oz can | 34mg per 12 oz can |
| Caffeine per fl oz | 5.8mg | 2.8mg |
| Servings to reach 400mg (FDA context) | 5.8 | 11.8 |
Sources: Pepsi Zero Sugar's figure is verified in our Pepsi Zero Sugar caffeine guide against PepsiCo product facts (source); Coca-Cola Classic's figure is verified in our Coca-Cola Classic guide against Caffeine Informer (source).
Which one should you pick?
Pick Coca-Cola Classic when you want the lighter dose or a slower ramp, and Pepsi Zero Sugar 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
- Coca-Cola Classic: 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 Coca-Cola Classic have more caffeine? Pepsi Zero Sugar: 69mg per 12 oz can versus 34mg per 12 oz can for Coca-Cola Classic.
Which is stronger per ounce? Pepsi Zero Sugar, at about 5.8mg per fluid ounce versus 2.8mg for Coca-Cola Classic.
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