Step 3: Cut Bottom Shelf
Determine how much space your drawer slides (normally 1" total) and the sides of the pull out drawers (if using 1/2” plywood, this distance is 1”, if using 3/4" material, this distance is 1-1/2”) will require, and subtract this number from the opening width of your cabinet.
Cabinet Opening =18"
Drawer Slide Clearance = 1"
Pullout Sides Thickness = 1"
Cut Width = 16"
Cut the bottom shelf to this width.
You may also need to cut the bottom shelf down in length to accommodate adding a front and back to it. I cut mine down by 1” (since I’m using 1/2” plywood on the front and back).