Dunkin iced coffee (medium) has more caffeine than Starbucks Flat White on both counts: 297mg per 24 oz medium against 195mg per 16 oz grande, and about 12mg per fluid ounce against 12. The serving sizes differ, so the table below shows both ways of counting.
Starbucks Flat White vs Dunkin iced coffee (medium): the numbers
| Starbucks Flat White | Dunkin iced coffee (medium) | |
|---|---|---|
| Caffeine per serving | 195mg per 16 oz grande | 297mg per 24 oz medium |
| Caffeine per fl oz | 12.2mg | 12.4mg |
| Servings to reach 400mg (FDA context) | 2.1 | 1.3 |
Sources: Starbucks Flat White's figure is verified in our Starbucks Flat White caffeine guide against Starbucks nutrition listing (source); Dunkin iced coffee (medium)'s figure is verified in our Dunkin iced coffee (medium) guide against Caffeine Informer Dunkin guide (source).
Which one should you pick?
Pick Starbucks Flat White 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
- Starbucks Flat White: 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
FAQ
Does Starbucks Flat White or Dunkin iced coffee (medium) have more caffeine? Dunkin iced coffee (medium): 297mg per 24 oz medium versus 195mg per 16 oz grande for Starbucks Flat White.
Which is stronger per ounce? Dunkin iced coffee (medium), at about 12.4mg per fluid ounce versus 12.2mg for Starbucks Flat White.
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