Mountain Dew Zero Sugar carries more total caffeine per serving (68mg per 12 oz can vs 47mg per 8 oz cup), but ounce for ounce English breakfast tea is actually the stronger drink at about 6mg per fluid ounce against 6. Which one "has more caffeine" depends on whether you measure the container or the concentration.
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.
Mountain Dew Zero Sugar vs English breakfast tea: the numbers
| Mountain Dew Zero Sugar | English breakfast tea | |
|---|---|---|
| Caffeine per serving | 68mg per 12 oz can | 47mg per 8 oz cup |
| Caffeine per fl oz | 5.7mg | 5.9mg |
| Servings to reach 400mg (FDA context) | 5.9 | 8.5 |
Sources: Mountain Dew Zero Sugar's figure is verified in our Mountain Dew Zero Sugar caffeine guide against PepsiCo product facts (source); English breakfast tea's figure is verified in our English breakfast tea guide against Twinings published figure (source).
Which one should you pick?
Pick English breakfast tea when you want the lighter dose or a slower ramp, and Mountain Dew Zero Sugar 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
- Mountain Dew Zero Sugar: the full caffeine guide
- English breakfast tea: the full caffeine guide
- The verified caffeine database
FAQ
Does Mountain Dew Zero Sugar or English breakfast tea have more caffeine? Mountain Dew Zero Sugar: 68mg per 12 oz can versus 47mg per 8 oz cup for English breakfast tea.
Which is stronger per ounce? English breakfast tea, at about 5.9mg per fluid ounce versus 5.7mg for Mountain Dew Zero Sugar.
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.