You may have heard that it's not ideal to crowd a skillet when sautéing or searing. Hot tip: the same thing holds true for sheet pans.
But that doesn't mean you should commit to only using the largest sheet pans you can find—some recipes require the smaller guys. That's why it's a good idea to have several sheet pans of varying sizes. Below, a round up of some of the most common sizes; an explanation on the differences between cookie sheets, regulation baking sheets, and jelly roll pans; and the best ways to use each.
Full Sheet
A full-sheet pan measures 26-by-18 inches and typically has sides that are about one inch high. They're generally too large for practical home use—in fact they won't fit in many home ovens. Instead, these are the workhorse pans of caterers and some restaurants (although, truthfully, they're pretty big for most restaurant kitchens, too). One way most home kitchens can use a full sheet pan: as an organizing bin for the pantry.
BUY IT: Winware Aluminum Full-Sheet Pan, $20 at Amazon
Half Sheet
Exactly half the size of full-sheet pans, half-sheet pans measure 18-by-13 inches, also with sides about one inch high. These are the pans we use most often in the Epicurious test kitchen, and it's the go-to pan for those sheet-pan dinners you keep reading about. We also use half-sheet pans for make-ahead breakfasts and desserts. It's a great pan for roasting vegetables, since it has plenty of surface area to spread the veg out, giving them room to brown and cook through evenly—some people even prefer it for roasting Thanksgiving turkey.
BUY IT: Nordic Ware Naturals Half-Sheet Pan, $25 for 2 at Amazon