Suntory Boss Coffee carries more total caffeine per serving (140mg per 8 oz can vs 120mg per 6.5 oz can), but ounce for ounce Starbucks Doubleshot Espresso & Cream is actually the stronger drink at about 18mg per fluid ounce against 18. Which one "has more caffeine" depends on whether you measure the container or the concentration.
Suntory Boss Coffee vs Starbucks Doubleshot Espresso & Cream: the numbers
| Suntory Boss Coffee | Starbucks Doubleshot Espresso & Cream | |
|---|---|---|
| Caffeine per serving | 140mg per 8 oz can | 120mg per 6.5 oz can |
| Caffeine per fl oz | 17.5mg | 18.5mg |
| Servings to reach 400mg (FDA context) | 2.9 | 3.3 |
Sources: Suntory Boss Coffee's figure is verified in our Suntory Boss Coffee caffeine guide against Caffeine Informer (source); Starbucks Doubleshot Espresso & Cream's figure is verified in our Starbucks Doubleshot Espresso & Cream guide against Caffeine Informer / Starbucks nutrition (source).
Which one should you pick?
Pick Starbucks Doubleshot Espresso & Cream when you want the lighter dose or a slower ramp, and Suntory Boss Coffee 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 Doubleshot Espresso & Cream: 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 Doubleshot Espresso & Cream have more caffeine? Suntory Boss Coffee: 140mg per 8 oz can versus 120mg per 6.5 oz can for Starbucks Doubleshot Espresso & Cream.
Which is stronger per ounce? Starbucks Doubleshot Espresso & Cream, at about 18.5mg per fluid ounce versus 17.5mg for Suntory Boss Coffee.
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