It was a mistake... someone dropped off some size 2 (12-18 lbs) diapers for our "officially" sized 4 (22- 37 lbs) faircompanies baby (she's 25 lbs). We try not to use disposables, but we've been having a cloth diaper buildup problem (see the "stripping your diapers" video) so we welcomed the small- too small?- gift. We noticed that the size 2 was about half the size of the 4 and could result in a substantial reduction of resources if our child could just drop a size, or two. Curious as to what would happen if we broke with those disposable diaper size charts, we dropped 2 sizes for our daughter and all went surprisingly well.