Starbucks Iced Coffee vs Rockstar Original: which has more caffeine?

Starbucks Iced Coffee vs Rockstar Original: which has more caffeine?

Starbucks Iced Coffee has more caffeine than Rockstar Original: 165mg vs 160mg in the same 16 oz grande. That is a 5mg gap, and since the servings match, the per-serving number is the whole story.

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.

Starbucks Iced Coffee vs Rockstar Original: the numbers

Starbucks Iced Coffee Rockstar Original
Caffeine per serving 165mg per 16 oz grande 160mg per 16 oz can
Caffeine per fl oz 10.3mg 10.0mg
Servings to reach 400mg (FDA context) 2.4 2.5

Sources: Starbucks Iced Coffee's figure is verified in our Starbucks Iced Coffee caffeine guide against Starbucks nutrition listing (source); Rockstar Original's figure is verified in our Rockstar Original guide against Rockstar product page (source).

Which one should you pick?

Pick Rockstar Original when you want the lighter dose or a slower ramp, and Starbucks Iced Coffee 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.

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FAQ

Does Starbucks Iced Coffee or Rockstar Original have more caffeine? Starbucks Iced Coffee: 165mg per 16 oz grande versus 160mg per 16 oz can for Rockstar Original.

Which is stronger per ounce? Starbucks Iced Coffee, at about 10.3mg per fluid ounce versus 10.0mg for Rockstar Original.

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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