On the bag of dog food is a chart that lists the age and the pounds of a dog with the quantity of food that is recommended - that's what I go by. I have a tendancy to overfeed my cats. I have 2 really fat cats. My spayed female is huge, way too big for her age, she must have gained at least 7 or 8 lbs since I had her spayed. I don't want to do that with my little Chi - these little dogs are inclined to be fat if you don't watch their diet (so I'm told). So I'd say, follow the chart on the bag of dog food as closely as you can.