Starbucks Vs Dunkin' Dark Roast: Which Coffee Has More Caffeine?

For some people, dark roast coffee is a treat that they savor for its rich, luxuriant flavor. For others, it's a vessel for pounding as much caffeine as humanly possible. For the latter group of people — the third-shifters and night owls among us — it makes sense to wonder which dark roast coffees offer the most bang for your buck in terms of caffeine content. Between the two American coffee giants, Starbucks and Dunkin', which dark roast has more go-go juice?

Starbucks uses arabica coffee beans, same as Dunkin' does. Yet, Starbucks' dark roast offers more caffeine per ounce than Dunkin's midnight dark roast blend. (It's important to note the "per ounce" distinction, because you'll have a hard time comparing the two if you don't take that into account.) For example, a 16-ounce "grande" dark roast Starbucks coffee contains 260 milligrams of caffeine. By contrast, a large Dunkin' brewed dark roast coffee, which is 20 ounces, has only 235 milligrams of caffeine.

Keep in mind that the way coffee is prepared has a lot to do with the resulting caffeine content. For instance, when it comes to caffeine, there is a difference between cold brew and iced coffee even if the drinks are the same volume and are made using the same beans. This is due to the temperature of the water that's used during the brewing process. Grind size and brewing method will also affect how caffeinated a coffee is, possibly explaining the difference between Starbucks and Dunkin'.

Wondering what coffee drink packs the biggest caffeine punch? At Starbucks, you actually need to think light: A venti blonde roast contains an impressive 410 milligrams of caffeine, much more than Starbucks' bevy of handcrafted drinks (which feature espresso shots) do. At Dunkin', one of the strongest offerings is the large iced coffee which contains 392 milligrams of caffeine.

Before you start searching out these powerful drinks, remember that the Food and Drug Administration recommends that adults top out at no more than 400 milligrams of caffeine a day, which includes any sodas, teas, or energy drinks that you might have in addition to your coffee. Given that, we'd suggest that it's best to slurp down these powerful coffees only occasionally.