Mountain Dew Zero Sugar has more caffeine than Coca-Cola Classic: 68mg vs 34mg in the same 12 oz can. That is a 34mg gap, and since the cans match, the per-serving number is the whole story.
Coca-Cola Classic vs Mountain Dew Zero Sugar: the numbers
| Coca-Cola Classic | Mountain Dew Zero Sugar | |
|---|---|---|
| Caffeine per serving | 34mg per 12 oz can | 68mg per 12 oz can |
| Caffeine per fl oz | 2.8mg | 5.7mg |
| Servings to reach 400mg (FDA context) | 11.8 | 5.9 |
Sources: Coca-Cola Classic's figure is verified in our Coca-Cola Classic caffeine guide against Caffeine Informer (source); Mountain Dew Zero Sugar's figure is verified in our Mountain Dew Zero Sugar guide against PepsiCo product facts (source).
Which one should you pick?
Pick Coca-Cola Classic 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
- Coca-Cola Classic: the full caffeine guide
- Mountain Dew Zero Sugar: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
FAQ
Does Coca-Cola Classic or Mountain Dew Zero Sugar have more caffeine? Mountain Dew Zero Sugar: 68mg per 12 oz can versus 34mg per 12 oz can for Coca-Cola Classic.
Which is stronger per ounce? Mountain Dew Zero Sugar, at about 5.7mg per fluid ounce versus 2.8mg for Coca-Cola Classic.
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.