Coca-Cola Classic has more caffeine than Barq's root beer: 34mg vs 22mg in the same 12 oz can. That is a 12mg gap, and since the cans match, the per-serving number is the whole story.
Barq's root beer vs Coca-Cola Classic: the numbers
| Barq's root beer | Coca-Cola Classic | |
|---|---|---|
| Caffeine per serving | 22mg per 12 oz can | 34mg per 12 oz can |
| Caffeine per fl oz | 1.8mg | 2.8mg |
| Servings to reach 400mg (FDA context) | 18.2 | 11.8 |
Sources: Barq's root beer's figure is verified in our Barq's root beer caffeine guide against Coca-Cola brand data (source); Coca-Cola Classic's figure is verified in our Coca-Cola Classic guide against Caffeine Informer (source).
Which one should you pick?
Pick Barq's root beer when you want the lighter dose or a slower ramp, and Coca-Cola Classic 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
- Barq's root beer: the full caffeine guide
- Coca-Cola Classic: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
FAQ
Does Barq's root beer or Coca-Cola Classic have more caffeine? Coca-Cola Classic: 34mg per 12 oz can versus 22mg per 12 oz can for Barq's root beer.
Which is stronger per ounce? Coca-Cola Classic, at about 2.8mg per fluid ounce versus 1.8mg for Barq's root beer.
Comparing caffeine? The caffeine comparison tool puts hundreds of drinks side by side, and the caffeine curfew calculator can check your cutoff time for tonight.