I don't know how much they weigh (9 weeks old, one is bigger than the other anyway). There is a chart on the back of the bag and I just guesstimated from that. I've been putting out 1/4 of a cup twice a day. They eat a bit here and there throughout the day. If I've put more than that in at a time they seem to take forever to eat it up, so I think this is probably ok, but I'm not sure. Right now I'm feeding them Iams kitty food (same as what they had at their foster home) and will switch them over to something better when we get near the end of the bag.