One medium chicken egg weighs approximately 45 grams and has 70 calories from 6 grams of protein, 5 grams of fat (1.4 gram of which is saturated), and less than 1 gram of carbohydrates. Almost 75% of an egg's weight is from water (33 grams). Of the 70 calories in a medium-sized egg, 62% are from fats, 36% are from protein, and the remaining 2% are from carbohydrates.