Rockstar Original has more caffeine than Aspire Energy on both counts: 160mg per 16 oz can against 80mg per 12 oz can, and about 10mg per fluid ounce against 7. The serving sizes differ, so the table below shows both ways of counting.
Aspire Energy vs Rockstar Original: the numbers
| Aspire Energy | Rockstar Original | |
|---|---|---|
| Caffeine per serving | 80mg per 12 oz can | 160mg per 16 oz can |
| Caffeine per fl oz | 6.7mg | 10.0mg |
| Servings to reach 400mg (FDA context) | 5.0 | 2.5 |
Sources: Aspire Energy's figure is verified in our Aspire Energy caffeine guide against Aspire / Caffeine Informer (source); Rockstar Original's figure is verified in our Rockstar Original guide against Rockstar product page (source).
Which one should you pick?
Pick Aspire Energy 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
- Aspire Energy: 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 Aspire Energy or Rockstar Original have more caffeine? Rockstar Original: 160mg per 16 oz can versus 80mg per 12 oz can for Aspire Energy.
Which is stronger per ounce? Rockstar Original, at about 10.0mg per fluid ounce versus 6.7mg for Aspire Energy.
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