How big is a newborn's stomach?:

By Let Mommy Sleep. November 6, 2014

At birth, a newborn baby's stomach is very tiny, about the size of a cherry. Don’t be swayed by even the tiniest bottle. Even the tiny hospital bottles are way too much for the first two weeks of baby's life. New parents need to be careful not to overfeed in the first weeks of life.  Overfeeding does not help baby sleep, in fact, it causes unnecessary spit up and gastric discomfort.

Small, frequent feeds, sometimes up to 12 feeds per 24 hour period are the norm in baby’s first weeks. If it feels like, “All I’m doing is nursing/feeding!” then chances are you’re doing everything right. For breastfeeding moms, milk typically "comes in" on about day four or five after baby's birth.  

Small frequent feeds are the norm during this time. Our helpful visual below shows the volume of a newborn's stomach: Howbigisanewbornsstomach