Well it depends how much you use. If you add a tablespoon, I think it's 160 calories. But these are very healthy fats in olive oil, just make sure it fits into your daily requirements!
Someone else may be able to confirm or deny this, but I have heard that you shouldn't actually cook with the olive oil. Apparently when you raise the temperature it changes the form of it rendering it much less healthy. I always cook without the olive oil and then spoon it on top. Does anyone know if there is truth to this??