The Classic McDonald's Hamburger starts with a 100% pure beef patty seasoned with just a pinch of salt and pepper. Then, the McDonald’s burger is topped with a tangy pickle, chopped onions, ketchup, and mustard. What's the difference between a Hamburger and a Cheeseburger, you ask? A slice of cheese in the latter! There are 250 calories in a McDonald’s Hamburger. It contains no artificial flavors, preservatives, or added colors from artificial sources.*