Starbucks cold brew (grande) carries more total caffeine per serving (205mg per 16 oz grande vs 140mg per 8 oz can), but ounce for ounce Suntory Boss Coffee is actually the stronger drink at about 18mg per fluid ounce against 13. 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.
Suntory Boss Coffee vs Starbucks cold brew (grande): the numbers
| Suntory Boss Coffee | Starbucks cold brew (grande) | |
|---|---|---|
| Caffeine per serving | 140mg per 8 oz can | 205mg per 16 oz grande |
| Caffeine per fl oz | 17.5mg | 12.8mg |
| Servings to reach 400mg (FDA context) | 2.9 | 2.0 |
Sources: Suntory Boss Coffee's figure is verified in our Suntory Boss Coffee caffeine guide against Caffeine Informer (source); Starbucks cold brew (grande)'s figure is verified in our Starbucks cold brew (grande) guide against Starbucks menu data (source).
Which one should you pick?
Pick Suntory Boss Coffee when you want the lighter dose or a slower ramp, and Starbucks cold brew (grande) 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
- Suntory Boss Coffee: the full caffeine guide
- Starbucks cold brew (grande): the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
- Compare any two of 120+ drinks
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Gear from this guide
FAQ
Does Suntory Boss Coffee or Starbucks cold brew (grande) have more caffeine? Starbucks cold brew (grande): 205mg per 16 oz grande versus 140mg per 8 oz can for Suntory Boss Coffee.
Which is stronger per ounce? Suntory Boss Coffee, at about 17.5mg per fluid ounce versus 12.8mg for Starbucks cold brew (grande).
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