Pepsi Zero Sugar has more caffeine than Mountain Dew: 69mg vs 54mg in the same 12 oz can. That is a 15mg gap, and since the cans match, the per-serving number is the whole story.
Pepsi Zero Sugar vs Mountain Dew: the numbers
| Pepsi Zero Sugar | Mountain Dew | |
|---|---|---|
| Caffeine per serving | 69mg per 12 oz can | 54mg per 12 oz can |
| Caffeine per fl oz | 5.8mg | 4.5mg |
| Servings to reach 400mg (FDA context) | 5.8 | 7.4 |
Sources: Pepsi Zero Sugar's figure is verified in our Pepsi Zero Sugar caffeine guide against PepsiCo product facts (source); Mountain Dew's figure is verified in our Mountain Dew guide against Caffeine Informer (source).
Which one should you pick?
Pick Mountain Dew when you want the lighter dose or a slower ramp, and Pepsi 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
- Pepsi Zero Sugar: the full caffeine guide
- Mountain Dew: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
- Compare any two of 120+ drinks
FAQ
Does Pepsi Zero Sugar or Mountain Dew have more caffeine? Pepsi Zero Sugar: 69mg per 12 oz can versus 54mg per 12 oz can for Mountain Dew.
Which is stronger per ounce? Pepsi Zero Sugar, at about 5.8mg per fluid ounce versus 4.5mg for Mountain Dew.
Barista Life runs on coffee people. Browse the Barista Life shop to support the site.