Aspire Energy has more caffeine than Diet Coke: 80mg vs 46mg in the same 12 oz can. That is a 34mg gap, and since the cans match, the per-serving number is the whole story.
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.
Aspire Energy vs Diet Coke: the numbers
| Aspire Energy | Diet Coke | |
|---|---|---|
| Caffeine per serving | 80mg per 12 oz can | 46mg per 12 oz can |
| Caffeine per fl oz | 6.7mg | 3.8mg |
| Servings to reach 400mg (FDA context) | 5.0 | 8.7 |
Sources: Aspire Energy's figure is verified in our Aspire Energy caffeine guide against Aspire / Caffeine Informer (source); Diet Coke's figure is verified in our Diet Coke guide against Caffeine Informer (source).
Which one should you pick?
Pick Diet Coke when you want the lighter dose or a slower ramp, and Aspire Energy 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
- Aspire Energy: the full caffeine guide
- Diet Coke: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
- Compare any two of 120+ drinks
FAQ
Does Aspire Energy or Diet Coke have more caffeine? Aspire Energy: 80mg per 12 oz can versus 46mg per 12 oz can for Diet Coke.
Which is stronger per ounce? Aspire Energy, at about 6.7mg per fluid ounce versus 3.8mg for Diet Coke.
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