Rockstar XDurance has more caffeine than Red Bull on both counts: 300mg per 16 oz can against 80mg per 8.4 oz can, and about 19mg per fluid ounce against 10. The serving sizes differ, so the table below shows both ways of counting.
Rockstar XDurance vs Red Bull: the numbers
| Rockstar XDurance | Red Bull | |
|---|---|---|
| Caffeine per serving | 300mg per 16 oz can | 80mg per 8.4 oz can |
| Caffeine per fl oz | 18.8mg | 9.5mg |
| Servings to reach 400mg (FDA context) | 1.3 | 5.0 |
Sources: Rockstar XDurance's figure is verified in our Rockstar XDurance caffeine guide against Rockstar product page / Caffeine Informer (source); Red Bull's figure is verified in our Red Bull guide against Red Bull label / Caffeine Informer (source).
Which one should you pick?
Pick Red Bull when you want the lighter dose or a slower ramp, and Rockstar XDurance 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 XDurance: the full caffeine guide
- Red Bull: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
- Compare any two of 120+ drinks
FAQ
Does Rockstar XDurance or Red Bull have more caffeine? Rockstar XDurance: 300mg per 16 oz can versus 80mg per 8.4 oz can for Red Bull.
Which is stronger per ounce? Rockstar XDurance, at about 18.8mg per fluid ounce versus 9.5mg for Red Bull.
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