Starbucks Refreshers vs Dunkin iced coffee (medium): which has more caffeine?

Dunkin iced coffee (medium) has more caffeine than Starbucks Refreshers on both counts: 297mg per 24 oz medium against 45mg per 16 oz grande, and about 12mg per fluid ounce against 3. The serving sizes differ, so the table below shows both ways of counting.

Starbucks Refreshers vs Dunkin iced coffee (medium): the numbers

Sources: Starbucks Refreshers's figure is verified in our Starbucks Refreshers 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).

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 Starbucks Refreshers 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 Refreshers: 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 Refreshers or Dunkin iced coffee (medium) have more caffeine? Dunkin iced coffee (medium): 297mg per 24 oz medium versus 45mg per 16 oz grande for Starbucks Refreshers.

Which is stronger per ounce? Dunkin iced coffee (medium), at about 12.4mg per fluid ounce versus 2.8mg for Starbucks Refreshers.