Rockstar Pure Zero vs Starbucks cold brew (grande): which has more caffeine?

Rockstar Pure Zero has more caffeine than Starbucks cold brew (grande): 240mg vs 205mg in the same 16 oz can. That is a 35mg gap, and since the cans 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.

Rockstar Pure Zero vs Starbucks cold brew (grande): the numbers

Sources: Rockstar Pure Zero's figure is verified in our Rockstar Pure Zero caffeine guide against Caffeine Informer (source); Starbucks cold brew (grande)'s figure is verified in our Starbucks cold brew (grande) guide against Starbucks menu data (source).

Which one should you pick?

Pick Starbucks cold brew (grande) when you want the lighter dose or a slower ramp, and Rockstar Pure Zero 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

• Rockstar Pure Zero: the full caffeine guide
• Starbucks cold brew (grande): the full caffeine guide
• The verified caffeine database
• Every drink compared: the comparisons index
• Compare any two of 120+ drinks

FAQ

Does Rockstar Pure Zero or Starbucks cold brew (grande) have more caffeine? Rockstar Pure Zero: 240mg per 16 oz can versus 205mg per 16 oz grande for Starbucks cold brew (grande).

Which is stronger per ounce? Rockstar Pure Zero, at about 15.0mg per fluid ounce versus 12.8mg for Starbucks cold brew (grande).