Costa Americano Calories

It doesn't take a lot, but I am foncused! :) I was always under the impression that if you have a black americano coffee that there is little to no calorific content (ie 1 or 2 kcals) as essentially the majority of your drink is hot water. Yet if I go to Costa or Starbucks for nutritional information a filter coffee is 12 or 6 calories respectively? I'm sure this has been discussed to death here already. :)