How Many Diapers Do I Need? - Babylist
Mar 23, 2020·Gender can play a part in how soon you need to size up. Average-size baby boys usually move into Size 1 diapers around four weeks old and Size 2 diapers at about three to four months. Average-size baby reach the same milestones later, transitioning into Size 1 diapers around six weeks and Size 2 diapers between four or five months.