My daughters like baby quilts that are 50x60. I personally like 45x55. The problem with trying to have the baby quilt stay smaller then the width of fabric is that it is really a little narrow for when the baby gets slightly older. I find Connecting Threads fabrics seem to be closer to 44 wide while Joanns seem smaller then 40 wide.

Thank you everyone, your answers are very helpful. I appreciate it

I make most of mine 45 x 60. That size is great for a crib or on the floor. I use a 1" thick poly batting so they are really fluffy & not hard to quilt at all on my domestic machine. I don't make any of them square.

I go thru the same thing. They can be any size from 36" to 52". There is not a set size. I know that back in the 80s, the pre-quilted baby panels were 36" x 44".

Baby quilts to me are the only square quilts that I make. I call them tummy time quilts. They are at least 36 x 36 and no more than 48 x 48. If I made a rectangular one from a pattern I couldn't resist, I would probably add a hanging sleeve for the nursery. Since they don't recommend any blankets in the cribs, these days, it could be decoration.

I rarely make the normal size quilt for babies. I feel they should grow with the baby so mine usually turn out around 60 x 70 or there abouts. Getting ready to make a couple quilts for a set of twins due at the end of July. Still waiting to hear the sex for the 2nd one as he/she seems to like to hide behind the brother (1st one).

I like to make baby quilts the width of the flannel yardage with which I back them, which is about 42". The other direction, for a new baby, is usually about 36". I guess that means that I would add a 2" border to your 31 x 40 top.
I think playpen size is about 40 x42 -- I know they're not exactly square.
Maximum baby quilt size, to me, is 42 x 50 which should work as long as the baby is in a standard crib.

I make my baby quilts crib size -- and whether or not you piece the back depends upon what fabric you use for your backing! I frequently purchase percale in 90" or 108" yardage and use that for backing. As has been said, though, the size you make your baby quilts is "your decision". We don't have quilt police around here, thank God!

Jeanette

I like the 40 wide for the "not having to piece the backing". Usually go with 48"in.- 56"in. for length.

For receiving blankets, I like square. I've done different sizes. Just depends on the use.