Mountain Dew Zero Sugar carries more total caffeine per serving (68mg per 12 oz can vs 63mg per 1 oz shot), but ounce for ounce espresso is actually the stronger drink at about 63mg 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 espresso: the numbers
| Mountain Dew Zero Sugar | espresso | |
|---|---|---|
| Caffeine per serving | 68mg per 12 oz can | 63mg per 1 oz shot |
| Caffeine per fl oz | 5.7mg | 63.0mg |
| Servings to reach 400mg (FDA context) | 5.9 | 6.3 |
Sources: Mountain Dew Zero Sugar's figure is verified in our Mountain Dew Zero Sugar caffeine guide against PepsiCo product facts (source); espresso's figure is verified in our espresso guide against USDA FoodData Central (source).
The concentration gap is the striking part: espresso packs roughly 11 times the caffeine per ounce. Sipping speed matters at that density; a 1 oz shot finished in minutes hits differently than the same milligrams spread over a slow cup.
Which one should you pick?
Pick espresso 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
- espresso: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
FAQ
Does Mountain Dew Zero Sugar or espresso have more caffeine? Mountain Dew Zero Sugar: 68mg per 12 oz can versus 63mg per 1 oz shot for espresso.
Which is stronger per ounce? espresso, at about 63.0mg 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.