how many ounces?

Desiree
My son is 5 months and I breastfeed him every 2-3 hours except overnight where it is every 3-4 hours.
For the past 2 weeks it seems like he isn't getting enough so we started offering him an 1-2 ounces of formula when he was still fussy
How many ounces were your babies eating around this age? I just don't want to overfeed or underfeed him