A sausage, egg and cheese biscuit contains about 575 calories. The bulk of those calories come from the biscuit, which is a high-fat bread.
One 125-gram turkey and pork sausage patty, after it is fully cooked, contains 77 calories.
One large egg has 72 calories. For an egg fried in butter, 1/2 tbsp. of butter contains 51 calories.
The calories in the cheese depend on what kind you use. A 1-ounce slice of cheddar cheese contains 114 calories. A 1-ounce slice of processed American cheese has 94 calories. If you use processed fat-free American cheese, that lowers the calorie count to 82.
One large, 77-gram buttermilk biscuit contains 281 calories. Perhaps more importantly from a health standpoint, it has almost 13 g of fat. In contrast, a slice of multigrain bread also weighing 77 g contains 204 calories and 3.26 g of fat.