Mountain Dew has the most caffeine of the three at 54mg per 12 oz can, Pepsi sits in the middle at 38mg, and Coca-Cola Classic has the least at 34mg. The servings are identical, so the per-can numbers settle it outright: a 20mg spread from top to bottom.
Coca-Cola Classic vs Pepsi vs Mountain Dew: the numbers
| Coca-Cola Classic | Pepsi | Mountain Dew | |
|---|---|---|---|
| Caffeine per serving | 34mg per 12 oz can | 38mg per 12 oz can | 54mg per 12 oz can |
| Caffeine per fl oz | 2.8mg | 3.2mg | 4.5mg |
| Servings to reach 400mg (FDA context) | 11.8 | 10.5 | 7.4 |
Sources: Coca-Cola Classic is 34mg per 12 oz can per Caffeine Informer (source), and the figure is carried in our Coca-Cola Classic guide; Pepsi is 38mg per 12 oz can per Caffeine Informer (source), and the figure is carried in our Pepsi guide; Mountain Dew is 54mg per 12 oz can per Caffeine Informer (source), and the figure is carried in our Mountain Dew guide.
What a 20mg spread actually feels like
All three come in the same 12 oz can, so the gap is the whole difference. 20mg is less than half a cup of brewed coffee, which is the easiest way to size it if you already know your coffee tolerance. Switching from Coca-Cola Classic to Mountain Dew once a day changes your weekly intake by about 140mg.
The three head-to-head pages
Each pairing has its own page with the full math:
- Coca-Cola Classic vs Pepsi, head to head
- Coca-Cola Classic vs Mountain Dew, head to head
- Pepsi vs Mountain Dew, head to head
Which one should you pick?
Take Coca-Cola Classic when you want the smallest dose of the three, Pepsi when you want a middle number without thinking about it, and Mountain Dew when you actually want the 54mg and know how you handle it. If you drink more than one caffeinated thing a day, the useful move is adding the day up against the 400mg reference rather than judging each drink alone.
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
- 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
Which has the most caffeine, Coca-Cola Classic, Pepsi or Mountain Dew? Mountain Dew, at 54mg per 12 oz can. Pepsi has 38mg per 12 oz can and Coca-Cola Classic has 34mg per 12 oz can.
Which of the three is strongest per ounce? Mountain Dew, at about 4.5mg per fluid ounce, ahead of Pepsi at 3.2mg and Coca-Cola Classic at 2.8mg.
How many Mountain Dew servings reach the FDA 400mg reference? About 7.4 of them, at 12 oz can each. The FDA cites 400mg a day as an amount generally not associated with negative effects in healthy adults. This is information, not advice.
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