Rockstar XDurance has more caffeine than Monster: 300mg vs 160mg in the same 16 oz can. That is a 140mg gap, and since the cans match, the per-serving number is the whole story.
Rockstar XDurance vs Monster: the numbers
| Rockstar XDurance | Monster | |
|---|---|---|
| Caffeine per serving | 300mg per 16 oz can | 160mg per 16 oz can |
| Caffeine per fl oz | 18.8mg | 10.0mg |
| Servings to reach 400mg (FDA context) | 1.3 | 2.5 |
Sources: Rockstar XDurance's figure is verified in our Rockstar XDurance caffeine guide against Rockstar product page / Caffeine Informer (source); Monster's figure is verified in our Monster guide against Caffeine Informer (source).
Which one should you pick?
Pick Monster 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
- Monster: 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 Monster have more caffeine? Rockstar XDurance: 300mg per 16 oz can versus 160mg per 16 oz can for Monster.
Which is stronger per ounce? Rockstar XDurance, at about 18.8mg per fluid ounce versus 10.0mg for Monster.
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