I can't answer for a newborn, as I only started using MCN later on. But I would say for one child (other than newborn) you would probably want about 20 nappies all up. I had 32 for both boys when they were both in nappies and it was manageable, but a few more would have taken the pressure off with the washing. What sort of Baby Beehinds do you want to get? I had mostly Bamboo fitteds with some Magicalls for day care. But now with just one in nappies and he's not a huge wetter I use the Magicalls all the time except at night.