Barista Life Blog · 1 min read

Rockstar Original vs Diet Coke: which has more caffeine?

Rockstar Original has more caffeine than Diet Coke on both counts: 160mg per 16 oz can against 46mg per 12 oz can, and about 10mg per fluid ounce against 4. The serving sizes differ, so the table below shows both ways of counting.

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.

Rockstar Original vs Diet Coke: the numbers

Rockstar Original Diet Coke
Caffeine per serving 160mg per 16 oz can 46mg per 12 oz can
Caffeine per fl oz 10.0mg 3.8mg
Servings to reach 400mg (FDA context) 2.5 8.7

Sources: Rockstar Original's figure is verified in our Rockstar Original caffeine guide against Rockstar product page (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 Rockstar Original 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

FAQ

Does Rockstar Original or Diet Coke have more caffeine? Rockstar Original: 160mg per 16 oz can versus 46mg per 12 oz can for Diet Coke.

Which is stronger per ounce? Rockstar Original, at about 10.0mg per fluid ounce versus 3.8mg for Diet Coke.

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.

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