Dunkin iced coffee (medium) has more caffeine than Diet Dr Pepper on both counts: 297mg per 24 oz medium against 41mg per 12 oz can, and about 12mg 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 Dr Pepper vs Dunkin iced coffee (medium): the numbers
| Diet Dr Pepper | Dunkin iced coffee (medium) | |
|---|---|---|
| Caffeine per serving | 41mg per 12 oz can | 297mg per 24 oz medium |
| Caffeine per fl oz | 3.4mg | 12.4mg |
| Servings to reach 400mg (FDA context) | 9.8 | 1.3 |
Sources: Diet Dr Pepper's figure is verified in our Diet Dr Pepper caffeine guide against Caffeine Informer (source); Dunkin iced coffee (medium)'s figure is verified in our Dunkin iced coffee (medium) guide against Caffeine Informer Dunkin guide (source).
The concentration gap is the striking part: Dunkin iced coffee (medium) packs roughly 4 times the caffeine per ounce. Sipping speed matters at that density; a 24 oz medium finished in minutes hits differently than the same milligrams spread over a slow cup.
Which one should you pick?
Pick Diet Dr Pepper when you want the lighter dose or a slower ramp, and Dunkin iced coffee (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 Dr Pepper: the full caffeine guide
- Dunkin iced coffee (medium): the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
- Compare any two of 120+ drinks
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Gear from this guide
FAQ
Does Diet Dr Pepper or Dunkin iced coffee (medium) have more caffeine? Dunkin iced coffee (medium): 297mg per 24 oz medium versus 41mg per 12 oz can for Diet Dr Pepper.
Which is stronger per ounce? Dunkin iced coffee (medium), at about 12.4mg per fluid ounce versus 3.4mg for Diet Dr Pepper.
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.
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