Poppi Classic Cola has more caffeine than Diet Pepsi: 40mg vs 35mg in the same 12 oz can. That is a 5mg gap, and since the cans match, the per-serving number is the whole story.
Diet Pepsi vs Poppi Classic Cola: the numbers
| Diet Pepsi | Poppi Classic Cola | |
|---|---|---|
| Caffeine per serving | 35mg per 12 oz can | 40mg per 12 oz can |
| Caffeine per fl oz | 2.9mg | 3.3mg |
| Servings to reach 400mg (FDA context) | 11.4 | 10.0 |
Sources: Diet Pepsi's figure is verified in our Diet Pepsi caffeine guide against Caffeine Informer (source); Poppi Classic Cola's figure is verified in our Poppi Classic Cola guide against Caffeine Informer (source).
Which one should you pick?
Pick Diet Pepsi when you want the lighter dose or a slower ramp, and Poppi Classic Cola 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
- Poppi Classic Cola: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
FAQ
Does Diet Pepsi or Poppi Classic Cola have more caffeine? Poppi Classic Cola: 40mg per 12 oz can versus 35mg per 12 oz can for Diet Pepsi.
Which is stronger per ounce? Poppi Classic Cola, at about 3.3mg per fluid ounce versus 2.9mg for Diet Pepsi.
Comparing caffeine? The caffeine comparison tool puts hundreds of drinks side by side, and the caffeine curfew calculator can check your cutoff time for tonight.