You have three choices. (1) You could use the pallet "as Is" which is 40" X 48". This would work well if you had access to both sides of the shelves. (2) Cut the pallets in half to create two shelves 20" deep X 48" wide. or (3) Cut them in half you have shelves 24" deep X 40" wide. We chose this option because , if you look at the construction of a pallet, you will see that this is the easiest option in terms of additional bracing and ease of cutting. Two additional factors were: (1) These shelves are up against a wall and 40 or 48 inches is too deep to use full pallets and (2) 10 feet (120") long fit our floor [three pallets X 40"] and 12 feet (144") did not. Anyway this project could work from 1 pallet wide to ?.