RC Cola has more caffeine than Coca-Cola Zero Sugar: 43mg vs 34mg in the same 12 oz bottle. That is a 9mg gap, and since the bottles match, the per-serving number is the whole story.
RC Cola vs Coca-Cola Zero Sugar: the numbers
| RC Cola | Coca-Cola Zero Sugar | |
|---|---|---|
| Caffeine per serving | 43mg per 12 oz bottle | 34mg per 12 oz can |
| Caffeine per fl oz | 3.6mg | 2.8mg |
| Servings to reach 400mg (FDA context) | 9.3 | 11.8 |
Sources: RC Cola's figure is verified in our RC Cola caffeine guide against Caffeine Informer (source); Coca-Cola Zero Sugar's figure is verified in our Coca-Cola Zero Sugar guide against Caffeine Informer (source).
Which one should you pick?
Pick Coca-Cola Zero Sugar when you want the lighter dose or a slower ramp, and RC Cola 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
- RC Cola: the full caffeine guide
- Coca-Cola Zero Sugar: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
- Compare any two of 120+ drinks
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Gear from this guide
FAQ
Does RC Cola or Coca-Cola Zero Sugar have more caffeine? RC Cola: 43mg per 12 oz bottle versus 34mg per 12 oz can for Coca-Cola Zero Sugar.
Which is stronger per ounce? RC Cola, at about 3.6mg per fluid ounce versus 2.8mg for Coca-Cola Zero Sugar.
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