I Made this shelf to fit an Ikea shelf that i have to organize my 3D printer tools. it is about 267mm ( 10.5" ) tall with the 2 pieces together, 245mm ( 9 5/8" ) wide & 115mm ( 4.5" ) deep. each shelf has a small rib under the front of it to add strength. I printed it in PLA and it is easily strong enough for the tools I have in it.
Amazon Basics PLA