Enter the inside size of the box and the thickness of your sheet. You get an SVG or PDF your laser cutter can run, with every edge already cut into interlocking tabs.
You give the empty space inside the box and the thickness of the sheet. The generator draws a front, back, two sides, a bottom and a top, then cuts every shared edge into tabs. Wherever one panel has a tab, its neighbour has a matching gap, so each corner locks.
Because the sizes are inside sizes, the outside grows by one thickness on every face. A 100 mm cube in 3 mm ply measures 106 mm across.
Every edge is split into an odd count of equal sections. With an odd count, both ends of the edge start with a tab, so the edge reads the same in either direction. Flip a panel end for end and it still fits.
That means a closed box has only three distinct shapes: top and bottom match, front and back match, and the two sides match. A loose lid adds a fourth.
Measure the sheet with calipers in a few places. Ply sold as 3 mm is often 2.7 to 3.2 mm, and acrylic varies between sheets.
Tabs are exactly as deep as the thickness you enter. Too little and they stop short of the outside face. Too much and they stand proud, which sands flush quickly. When readings disagree, use the largest.
Leave it empty and each tab is about three times the thickness. A value you enter is treated as a target: it is adjusted so a whole, odd number of tabs fills each edge exactly.
It can range from 5 mm (about 0.2″) up to a third of the shortest outside edge, which guarantees at least three tabs per edge.
The beam burns away a thin strip, usually 0.1 to 0.2 mm on a CO₂ laser. Cut the drawing as-is and tabs come out narrow while gaps come out wide, so the joints rattle.
The generator grows every outline by half the kerf on each side. Raise it for a tighter fit. Wood takes a snug press fit; acrylic cracks if forced, so aim for a firm slide and glue it.
Before a big job, cut a small box from the same sheet with the same settings. Panels falling apart means raise the kerf a little; needing a mallet means lower it. Note the value that works for each material.
The files open in LightBurn, Inkscape, Illustrator and CorelDRAW. Add holes or engraving there, keeping them clear of the tabs.
Kerf matters most. It is the width the laser burns away, and the drawing makes up for it so tabs fit snugly. The colour shows how the box will likely fit for a typical CO₂ laser.
Saving files isn't available in this view. Copy the SVG below and paste it into a file named box.svg.
Both files hold the same panels. Page size, layout and the dimension block apply to the PDF only.