C4 Smart Energy has more caffeine than Rockstar Original: 200mg vs 160mg in the same 16 oz can. That is a 40mg gap, and since the cans match, the per-serving number is the whole story.
C4 Smart Energy vs Rockstar Original: the numbers
| C4 Smart Energy | Rockstar Original | |
|---|---|---|
| Caffeine per serving | 200mg per 16 oz can | 160mg per 16 oz can |
| Caffeine per fl oz | 12.5mg | 10.0mg |
| Servings to reach 400mg (FDA context) | 2.0 | 2.5 |
Sources: C4 Smart Energy's figure is verified in our C4 Smart Energy caffeine guide against Cellucor / 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 Rockstar Original when you want the lighter dose or a slower ramp, and C4 Smart Energy 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
- C4 Smart 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 C4 Smart Energy or Rockstar Original have more caffeine? C4 Smart Energy: 200mg per 16 oz can versus 160mg per 16 oz can for Rockstar Original.
Which is stronger per ounce? C4 Smart Energy, at about 12.5mg per fluid ounce versus 10.0mg for Rockstar Original.
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