This all depends on types of diapers and how often you wash. For example, when we use fitteds or prefolds in a cover, I change more often. But using pocket diapers like FuzziBunz or BumGenius, we can go longer between changes. And I usually wash every day, so I don't need a huge stash. But if you don't want to do laundry every day, you'll need more. Personally, it's become such a habit of throwing in the diaper load every afternoon, I don't really think about it.
Our stash right now is 7 FuzziBunz Mediums, 4 BumGenius one size, 2 other pocket diapers, a few fitteds and prefolds, and 4-5 covers. We usually only use the pockets and use the others for backup or at the end of the day when I don't want to "waste" using a pocket. Isn't that stupid? Why does it matter? But in my head, if Ingrid is going to be in her diaper only for an hour before bathtime, I don't want to use a pocket. Things like this will surprise you, so again, be flexible :)
I really like my stash. I have only used them on a toddler though, as we started cloth diapering when Ingrid was a year old. If I were to have a baby in cloth, I know I would need a lot more, as they wet a lot more. And people say different diapers do better for small baby's poo, which I never had to deal with either. But for me, this stash works really well. If I had to change anything, I would probably have more one size diapers, as the Medium FB are getting to fit funny. I should probably go up to the Large but I don't want to spend the money...And they do fit, so I'll just use what I have.
