How much is your LO eating?

Laura • My partner and I are expecting our first together in January :-)
Our son is 3.5 weeks old and has been eating 3oz of formula per feeding about every 3 hrs, sometimes less. Today we gave him 4 during the last two feedings and he finished it all. He seems satisfied after 3 so idk if him drinking 4 is just because it's there or because he really wants and needs it. I'm curious to know what other babies are Eating around this age.