Hm, my LO has about 5 ounces (sometimes less, but I always fill 5 ounces so I can make sure she has her fill) roughly every 3 hrs during the day and she'll go 8-9 hrs at night without a feed (unless she wakes in the night, which doesn't happen as much anymore). Seems she should be taking a bit more than that, but you can't really force a baby to eat can you?