English breakfast tea has more caffeine than Barq's root beer on both counts: 47mg per 8 oz cup against 22mg per 12 oz can, and about 6mg per fluid ounce against 2. The serving sizes differ, so the table below shows both ways of counting.
These are different categories of drink, which changes how the caffeine arrives. Energy drinks and sodas list an exact number because caffeine is a measured additive; brewed drinks vary with the beans and the brew, so their figures are compiled averages. The numbers here are the standard published values for each.
Barq's root beer vs English breakfast tea: the numbers
| Barq's root beer | English breakfast tea | |
|---|---|---|
| Caffeine per serving | 22mg per 12 oz can | 47mg per 8 oz cup |
| Caffeine per fl oz | 1.8mg | 5.9mg |
| Servings to reach 400mg (FDA context) | 18.2 | 8.5 |
Sources: Barq's root beer's figure is verified in our Barq's root beer caffeine guide against Coca-Cola brand data (source); English breakfast tea's figure is verified in our English breakfast tea guide against Twinings published figure (source).
The concentration gap is the striking part: English breakfast tea packs roughly 3 times the caffeine per ounce. Sipping speed matters at that density; a 8 oz cup finished in minutes hits differently than the same milligrams spread over a slow cup.
Which one should you pick?
Pick Barq's root beer when you want the lighter dose or a slower ramp, and English breakfast tea 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
- English breakfast tea: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
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Gear from this guide
FAQ
Does Barq's root beer or English breakfast tea have more caffeine? English breakfast tea: 47mg per 8 oz cup versus 22mg per 12 oz can for Barq's root beer.
Which is stronger per ounce? English breakfast tea, at about 5.9mg 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.
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