Counting Carbohydrate Servings. This method is a good way to get started. One serving of a starch, fruit, or dairy product count as one “carb,” or about 15 grams of carbohydrates. For example: slice of bread = 1 starch serving = 15 grams of carbohydrates. apple = 1 fruit serving = 15 grams of carbohydrates. cup of milk = 1 dairy serving ...