4 and 5 week old kittens, how much food?

I am fostering 2 kittens for a rescue. I'm feeding them wet cat food, one can between them,split throughout the day. They won't drink any water. They get 45 ml.s of milk,split between them, 4 times a day. I'm worried because the smallest Resa's tummy seems big all the time.
Am I feeding the right amount?

I think kittens this age should get as much food as they will eat.  The rounded tummy could very well be caused by worms.

Thank you Denice. The thing is, they will eat constantly. Whatever I put down, they eat it all. Penny, in my avatar, doesn't have the round belly. Our small one Resa does, since I moved them to my bathroom I haven't witnessed Resa poop. They both have URI, because our local high kill shelter is crawling with it. Both are on meds and feeling better now. Just worried now about feeding and the one's round belly. The vet won't worm them until they're older.

I would offer more than one can a day.  I would split one can between them at least 3 times a day.  You can mix their kitten milk in with the food and make it the consistency of gruel or oatmeal.  They should have access to dry crunchies all the time.  They aren't drinking water probably because they are getting enough from the kitten milk and the wet food. 

Thank you, they are eating a 5.5 ounce can a day. I put kibble in some water and they finally drank water. I guess because it smelled/tasted like food. If they start eating kibble and drinking water do I still do milk and wet food? The smaller one's belly seems big all the time, I've heard it could be worms?

I would continue offering wet food (this is good for all cats regardless age.) As for the milk, I would continue until they are around 6 wks.

And, yes, the distended or large belly is very likely worms. I'd talk to the vet or rescue about getting some Strongid for the kittens. It's a good (and safe) dewormer

They should have wet food daily.  It's best for them.  Continue wetting the wet food for a few more weeks yet.  Once they get the hang of eating the wet food, continue with the wet food being their main form of nutrition and leave down kitten kibble all the time.  Kittens have a very high metabolism rate and go through food like crazy!  Their output in the litter box testifies to this!  LOL  Have them checked for worms as that is usually the cause of distended bellies in kitties.

Thank ya'll very much. Our rescue's vet won't worm them until they are 6 weeks. Yes the litterbox is always very full lol!

Kittens do 4 things:  eat, play, use the box, and sleep...all the time!!  LOL

I wouldn't mix kibble with water. Mix a little water or milk in with their wet food if you are worried about fluid intake. Btw, Mixing water with dry kibble can be a breeding ground for bacteria- not good.

You really can't feed them too much. Don't worry about that. Let 'em eat until they pop

Thank you. Ours are beginning to play. Penny the oldest has learned how to jump on to the windowsill.