It seems to me the better question might be, "should you bother with a walk in closet or would it be better to stick with a reach in closet?" Clothing hanging on a rod typically sticks out 24 inches from the wall. Then, if any clothing is beyond arm's reach from the door, you need an aisleway. In my opinion, an aisleway less than 32" wide is claustrophobic. And, if you're thinking of hanging clothing on two perpendicular walls, keep in mind that even tho the poles cross in the corner, you can only hang clothing in the corner on ONE of the two poles. And whatever is hung in the corner is going to be hidden by clothing on the other pole. Garments hung in corners wind up seldom being chosen for wear because basically they're hidden away!

DH and I shared a 5x7 closet in our old house and when I was packing up to move to the new house, I found some dresses that I had not worn in over ten years tucked back into the corner! I had forgotten I still had them. So the corners of closets are not exactly prime space.

If you have a 5'7" reach-in closet (interior dimensions 5'7" x 2'), with a wide doorway you get 5'7" of useable hanging space.

If you have a 4 x 5'7" walk in closet, you can hang stuff along one 5'7" wall and along 2feet of one of the 4' walls. So it seems like you have 7'7" of hanging space. But 2 feet of that is in a "hidden corner" so all you really gain by doubling the square footage taken up by the closet is 2 feet of "hidden corner" space.

The other option with a 4'x5'7" closet might be to hang garments along the two 4' walls and have the door in the center of one of the long walls. With clothing on both 4ft walls, you get 8 feet of hanging space but only have an aisle down the middle that is 19 inches wide. From the doorway, you can reach into a closet maybe 3 feet. That means you have about 6 feet of useful space; again anything hung further in will likely seldom be worn because you'd have to squeeze into the claustrophobic aisle to find it.

Personally, I think that if the space available for a closet is smaller than 5x7, you're better off going with a reach-in and putting the extra sq footage into the bedroom.

As for how much closet space guests need, most of us don't travel with THAT many clothes anymore. One foot of clear rod is more than enough. In fact, the most useful "closet" space I've ever stayed in was a guest room where the hostess had put 3 nice heavy duty hooks along one wall spaced a little over 2 feet apart and then put pretty decorated clothes hangers on them. On showing me to the room, my hostess told me, "the hangers aren't art-work, feel free to use them and if you need more hangers let me know. It was great b/c I didn't have to worry that I'd accidentally leave something behind in the guest room closet that, like most, was filled with the family's overflow.

What most of us REALLY in a guest room need is a clear surface to set our suitcase on and sometimes an empty drawer...

If you think you may be in this house long enough to have your children and grandchildren coming to stay, you may want to have your walk-in big enough to set up a crib or at least a pack-n-play. We have this setup at my parent's beach house and several vacation homes we have used, and it is so nice to have a room to put the baby in and not have to tiptoe around him or her as we are getting ready. As a mom who has used that closet for the last 7 years for one baby or another, I would give up space in the bedroom to be able to use the closet in this way. This may not apply to you at all, but thought I would throw that out there.

I have a 4'x4' reach in closet in my guest room. The floor is mainly used for storage and the rod is empty. It works for our guests, mainly because the stuff on the floor of the closet is theirs (and we wish they would take it when they leave).

Never give guest more than a small closet. Use the space saved for your storage needs.