my kids are 3 months and we're feeding them around 5oz during the day (if i need to do something or take a nap), 6oz for the first bottle (formula) and 7oz for their last feeding (breastmilk)... the rest of the time, i just breastfeed on demand. i really don't think they take in 5oz...
how old is your baby and how much are you feeding them?