My 4 month old takes about 6-8 oz per feeding. Feed 4-5 times a day.
Definitely offer more :)
ETA: I think the difference is that breastmilk grows with the child, so as they get older, the breastmilk components change and the AMOUNT they drink doesnt necessarily go up.
With formula, it's components don't change, obviously, so they need more as they grow, in order to satisfy them.