I think a square about 40 inches is the best size for a receiving blanket. I like the self binding receiving blankets but now it seems flannel width is getting smaller sometimes only 40 inches once the selvedge is cut off so they end up a bit smaller. For a baby quilt I like to make it at least 40-45 inches or more, either square or rectangle, so it can be used as a floor/play quilt now and as a drag around quilt when the child gets bigger. No blankets or quilts should be used as a cover in the crib for safety reasons.