According to WebMD, for most dry cat food brands, an adult cat needs to be fed just a little under a cup of food per day. An adult cat requires approximately 30 calories per pound of body weight each day.
For an average-sized adult cat, around 8 pounds, his pet owner needs to feed him around 240 calories daily. Average-sized cats who eat canned food should consume about one 6-ounce can per day. Cat owners should carefully read the nutrition label for their particular brand before deciding how much to feed their cat since serving size and nutrition may vary.