calories in a reuben
1 Calories In Reuben Sandwich St. Patrick's Day Leftovers. 2  365 calories, 8g fat, 38g carbs, 31g protein, 5g fiber. 3  Calories In Reuben Casserole from Roger. 4  380 calories, 20g fat, 33g carbs, 18g protein, 5g fiber.