How many calories are in a cheeseburger with ketchup only?

The calorie content of a cheeseburger with ketchup only can vary based on the size and ingredients of the burger, but a typical fast-food cheeseburger contains around 300 to 500 calories. Adding ketchup usually adds about 20 calories per tablespoon. Therefore, a cheeseburger with ketchup might range from approximately 320 to 520 calories. For a more accurate count, it's best to refer to specific nutritional information from the restaurant or brand.