To calculate calories for each product in the catfood, look at the label and put the amounts given on the label into the appropriate boxes. The amount of carbohydrates will be calculated automatically, since most labels do not include that information. Although moisture, ash or fibre do not add to the calories, they add to the bulk of the food and are required to calculate the amount of carbohydrates contained. Click 'Calculate' to get the total calories for each product in the cat food and the percentage of total calories.