Starbucks Flat White vs Rockstar Original: which has more caffeine?

Starbucks Flat White has more caffeine than Rockstar Original: 195mg vs 160mg in the same 16 oz grande. 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.

Starbucks Flat White vs Rockstar Original: the numbers

Sources: Starbucks Flat White's figure is verified in our Starbucks Flat White 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 Flat White 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
• Rockstar Original: 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 Rockstar Original have more caffeine? Starbucks Flat White: 195mg per 16 oz grande versus 160mg per 16 oz can for Rockstar Original.

Which is stronger per ounce? Starbucks Flat White, at about 12.2mg per fluid ounce versus 10.0mg for Rockstar Original.