Starbucks canned Nitro (Black) has more caffeine than GURU Original on both counts: 155mg per 9.6 oz can against 140mg per 12 oz can, and about 16mg per fluid ounce against 12. 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.
Starbucks canned Nitro (Black) vs GURU Original: the numbers
| Starbucks canned Nitro (Black) | GURU Original | |
|---|---|---|
| Caffeine per serving | 155mg per 9.6 oz can | 140mg per 12 oz can |
| Caffeine per fl oz | 16.1mg | 11.7mg |
| Servings to reach 400mg (FDA context) | 2.6 | 2.9 |
Sources: Starbucks canned Nitro (Black)'s figure is verified in our Starbucks canned Nitro (Black) caffeine guide against PepsiCo product facts (source); GURU Original's figure is verified in our GURU Original guide against Caffeine Informer (source).
Which one should you pick?
Pick GURU Original when you want the lighter dose or a slower ramp, and Starbucks canned Nitro (Black) 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
- Starbucks canned Nitro (Black): the full caffeine guide
- GURU Original: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
FAQ
Does Starbucks canned Nitro (Black) or GURU Original have more caffeine? Starbucks canned Nitro (Black): 155mg per 9.6 oz can versus 140mg per 12 oz can for GURU Original.
Which is stronger per ounce? Starbucks canned Nitro (Black), at about 16.1mg per fluid ounce versus 11.7mg for GURU Original.
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.