Calories in a Monte Cristo. While calories may vary according to restaurant and the amount of ingredients used to make the sandwich, a typical Monte Cristo contains more than 1,000 calories. SkinnyKitchen.com states an average Monte Cristo has 1,122 calories. A typical, full-fat Monte Cristo sandwich provides 69 grams of fat, 2,138 milligrams of sodium, 56 grams of carbohydrates and 67 grams of protein, according to SkinnyKitchen.com.