This is a commonly asked question that unfortunately does not have a precise answer Kcup coffee contains between 75-125mg of caffeine per 6 fluid ounces. I know, I know, that really is not very helpful. But, there are so many variables that determine the amount of caffeine in a cup of coffee, it is near impossible to estimate an exact amount.
-Caffeine varies by roasting type. Contrary to popular belief light roast coffee contains more caffeine than dark roast. Beans that are roasted dark are exposed to prolonged heat which breaks down the caffeine.
-Different types of beans will produce more caffeine than others. The higher end, better tasting Arabica beans that produce Keurig Kcups have less caffeine than their cheaper Robusta counterparts.
-The finer that a coffee is ground the more caffeine it will contain. Keurig Kcups coffee is generally ground on the medium to finer side.
-The length of time a coffee is brewed or steeped will affect the amount of caffeine extracted. For example, french press coffee has one of the highest caffeine contents because the general process is to allow the coffee to steep for four minutes.
-The hotter the water used in brewing, the higher the caffeine. Although you should not brew above 212 degrees.
-Obviously, the amount of grounds used will change the caffeine content of the resulting cup of coffee. Extra bold Keurig Kcups contain twenty percent more coffee translating to a more caffeinated cup of joe.
As you can see there are just too many factors to determine an exact amount of caffeine in a Keurig Kcup. However, with all things considered an extra bold, medium roast, Keurig Kcup would be at the higher end of the spectrum.