How much formula at 2 months?!

My daughter is 2 months old (almost 9 weeks). She eats 4oz of formula every 4ish hours (although she's usually hungry closer to 3.5 hours). But after doing some research and seeing other people's posts, a lot of things are saying that at 2 months babies should have 5-6oz at a time. How much should a 2 month old be drinking at a time and how many hours in between?? So confused!