Question: how many calories is in a small shamrock shake?
Answer: Shamrock Shakes, like most milkshakes, are not for the calorie conscious. A small Shamrock Shake has 460 calories, according to McDonald's. It also has 13 grams of fat, 74 grams of carbs, and 10 grams of protein. About 120 of the shake's over 400 calories are calories from fat.