Clotted cream is 55 to 60 percent fat. At 28.3g per ounce, that comes to 15.6 to 17g. Using 9 calories per gram of fat, that equates to 140 to 153 calories per ounce. Add four calories for a gram of carbohydrates and the total comes to 144 to 157 calories per ounce.read more >>