The number of calories in your chicken and cheese quesadillas will depend on the size of the tortilla, the amount of chicken and cheese you use and which toppings you add. A typical serving is about 1/2 of a quesadilla made with two tortillas, or a whole quesadilla made by folding one tortilla around the filling.
A chicken quesadilla made with an 11-inch tortilla, 1 cup of cheddar cheese and 1/3 pound of chicken breast served with tomato and corn salsa has 1,290 calories. Cutting back on the cheese and chicken to 3/8 cup of cheese and 1/2 cup of chicken per tortilla results in a quesadilla serving that has 520 calories. Using 1/4 pound of chicken breast, 1/4 cup of reduced-fat cheese, 1/8 of an avocado and topping your quesadilla with salsa results in a dish that has 400 calories per serving. You can save even more calories by using a smaller tortilla and replacing part of the chicken with mushrooms. Such a quesadilla made with a 7 1/2-inch tortilla has about 350 calories per serving, and one made with a 5 1/2-inch tortilla has about 236 calories per serving.