Rockstar Original carries more total caffeine per serving (160mg per 16 oz can vs 155mg per 9.6 oz can), but ounce for ounce Starbucks canned Nitro (Black) is actually the stronger drink at about 16mg per fluid ounce against 10. Which one "has more caffeine" depends on whether you measure the container or the concentration.
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 Original vs Starbucks canned Nitro (Black): the numbers
| Rockstar Original | Starbucks canned Nitro (Black) | |
|---|---|---|
| Caffeine per serving | 160mg per 16 oz can | 155mg per 9.6 oz can |
| Caffeine per fl oz | 10.0mg | 16.1mg |
| Servings to reach 400mg (FDA context) | 2.5 | 2.6 |
Sources: Rockstar Original's figure is verified in our Rockstar Original caffeine guide against Rockstar product page (source); Starbucks canned Nitro (Black)'s figure is verified in our Starbucks canned Nitro (Black) guide against PepsiCo product facts (source).
Which one should you pick?
Pick Starbucks canned Nitro (Black) when you want the lighter dose or a slower ramp, and Rockstar Original 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 Original: the full caffeine guide
- Starbucks canned Nitro (Black): the full caffeine guide
- The verified caffeine database
FAQ
Does Rockstar Original or Starbucks canned Nitro (Black) have more caffeine? Rockstar Original: 160mg per 16 oz can versus 155mg per 9.6 oz can for Starbucks canned Nitro (Black).
Which is stronger per ounce? Starbucks canned Nitro (Black), at about 16.1mg per fluid ounce versus 10.0mg for Rockstar Original.
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