Dunkin Refresher (medium) has more caffeine than Diet Pepsi on both counts: 99mg per 24 oz medium against 35mg per 12 oz can, and about 4mg 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 Dunkin Refresher (medium): the numbers
| Diet Pepsi | Dunkin Refresher (medium) | |
|---|---|---|
| Caffeine per serving | 35mg per 12 oz can | 99mg per 24 oz medium |
| Caffeine per fl oz | 2.9mg | 4.1mg |
| Servings to reach 400mg (FDA context) | 11.4 | 4.0 |
Sources: Diet Pepsi's figure is verified in our Diet Pepsi caffeine guide against Caffeine Informer (source); Dunkin Refresher (medium)'s figure is verified in our Dunkin Refresher (medium) guide against Tasting Table / Dunkin figures (source).
Which one should you pick?
Pick Diet Pepsi when you want the lighter dose or a slower ramp, and Dunkin Refresher (medium) 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
- Dunkin Refresher (medium): the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
FAQ
Does Diet Pepsi or Dunkin Refresher (medium) have more caffeine? Dunkin Refresher (medium): 99mg per 24 oz medium versus 35mg per 12 oz can for Diet Pepsi.
Which is stronger per ounce? Dunkin Refresher (medium), at about 4.1mg 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.