How to build a plywood storage box

A five-sided box is the classic first build, and the one thing that catches people is a bottom that bows under load. Set your sizes below and the engine checks the panels, the bottom span and the joints.

Check your size first

Free, instant and no account. The engine checks it the way a structural engineer would, and says so plainly when it won't hold up.

What goes wrong on a storage box

The bottom sags: A wide bottom in thin plywood bows when you fill it. The check works out the span and tells you when it needs support underneath or thicker stock.
Screwing into plywood edges: Screws driven into the edge of thin plywood split it. Pre-drill, and use a screw sized for the panel, not the biggest one in the drawer.

The build, start to finish

Cut the bottom and four sides from the cut list.
Join the sides into a frame and check the diagonals match.
Fix the bottom.
Ease the edges, finish it and fill it.

The full plan has the exact cut list, a shopping list, a 3D view you can stand in your room, and step-by-step assembly for your sizes.

Other builds

Setting up your bench…

Build guides · Storage box