The first step in maintaining your dog's diet is being cognizant of their breed, size, allergies and lifestyle. (The information below is general and not specific to certain breeds, dogs with allergies or an exercise lifestyle, these recommendations may vary.) Below is a simple chart for dog sizes and the suggested amount of food (Adult dogs) Size (pounds) Amount of food (cups) 3 - 12 lbs ½ cups - 1 ¼ cups 13 - 20 lbs 1 ¼ cups - 1 ⅔ cups 21 - 35 lbs 1 ⅔ cups - 2 ⅓ cups 36 -