K-Cups are standardly portioned ground coffee and filter cups for use with the Keurig Brewing System.

Many coffee roasters are now producing K-cups filled with their particular blend of coffee.

The caffeine content of K-cups is a bit tricky to narrow down because of the varied brands and blends available.

However, we estimate that an 8oz cup of coffee using the standard 2oz K-Cup would yield between 100-140mg of caffeine.

According to our estimation K-cup consists of 2 tablespoons of ground coffee, a filter, and other packaging material for a total of 2 onces.

There are also "extra bold" K-Cups available and according to Keurig's website they have 30% more ground coffee in them (2.6 tablespoons) than the regular K-Cup.

This would increase the caffeine content to around 150mg/ 8oz cup.