How many calories are there in a tomato?

My wife does a lot of cooking with tomatoes, in particular a spicy pork and tomato casserole as the weather gets colder, however one of my favourite ways to enjoy them is sliced with a little olive oil (don't get a cheap olive oil – always a false economy!), balsamic vinegar some salt and some chopped basil (also from the greenhouse!). Team these with some bread for dipping and some buffalo mozzarella... wow I'm making myself hungry now!

Anyway for the health conscious tomato eater here is a bit of information on the calories in tomatoes:

1 Medium tomato of around 120 grams is equal to 26 calories.
1 serving of chopped tomatoes which is 180 grams works out to be 38 calories.

Which means a slice of tomato is about 3 calories!