I am not too sure on exactly how many you will need. It depends on the nappy type and you changing habits. I change Maggie when I think she needs it or just before going out. Also I have a number of different types of nappies, some more absorbent than others, so it can vary from day to day.

I switched Maggie over to cloth earlier this year, I don't think she notices much difference, except with some nappy clothing combos, her movement is a bit more restricted so she can't get up onto the couch. Bad for her, but good for me. She is a wriggle bum with changes, so they do take a bit longer now. I get the nappy on her then she runs away so I have to grab her back to put the cover on.