If you go on the Sears website you can search the various brands and all the specifications for each.

You can find dimensions for various machines online, as brutuses says. However, if you're going to get a vented dryer (most common type), be aware that you will probably need to add a significant amount of space behind the dryer for the vent hose, unless it can be vented out the side (and if side-venting makes sense for you). I'd say that adding 6" at the rear for the vent hose is probably safe, but look at the installation instructions for the machines you're interested in. Of course compact (24") machines will also have less depth, but they do not have the load capacity of full-size machines. The largest-capacity top-loading dryers have a bump-out on the back that adds to depth; however this should be included in published dimensions. I don't know how front-loaders compare with top-loaders in depth, that's easily checked.

The depth of most toploaders is 30 to 32 inches. The LG models (2101) is the smallest full size model that I know of in depth. It's 29.75 inches. But, it's depth with the door open is 51 inches, which is the standard depth with the door open for most top loaders.

steve is right. You should add about 5 to 6 inches to the dryer depth for the exhaust venting. For dryers that match the top loaders, the depth would be the same as the toploader (30 to 32 inches). I think the conventional dryers are smaller. You could cut the 5 to 6 inches down though by using a periscope vent.

The Best Buy website lets you filter the washer and dryers by depth, too. I haven't been on the Sears site.

Good luck.

PS: I only know all of this because I was looking for my washer/dryer options with a small space as well.

Sorry, I said "toploaders" in the above post. I meant "front loaders."