About the building bricks

Look up a part, or set the size

Type a part number into Part number — 3001 for the classic 2×4 brick, 3020 for the 2×4 plate, 3068b for a 2×2 tile — and the size below fills in. You can also search by size (2x4, plate 2x4) or by kind. About eighty common bricks, plates and tiles are listed, from a 1×1 up to a 12×24 brick. If your part isn’t listed, set the studs and the height yourself: any size from 1×1 to 24×24 works, and anything you type in the size fields can still be changed after a lookup.

Height is counted in plates. A plate is 1, a standard brick is 3 (9.6 mm), and a brick that is three bricks tall is 9. Top is normal studs, hollow studs, or smooth for a tile.

What’s underneath

The underside is hollow, like the real thing, and it is what makes the bricks hold. Under any brick two studs wide or more there is a tube at the middle of every four studs, and each stud of the brick below presses against those tubes. A brick one stud wide has a thin pin between each pair of studs instead. You don’t set any of this: it follows the size.

Making it fit your printer

Printed parts never match the drawing exactly, and a brick only works if the studs are close to right. Two settings tune it:

• Stud clearance makes the studs narrower than the standard 4.8 mm. Printed studs come out slightly fat, so the default 0.1 mm gives a snap that holds without forcing. Too tight to press on: raise it by 0.05. Falls off: lower it.
• Side clearance is the gap on each side of the brick (0.1 mm on real bricks), so neighbours sit side by side without binding. Raise it if your printer swells the outside.

The quickest way to tune both is to print the fit test preset — a 2×2 plate — press it onto a real brick and onto another print, and adjust from there.

Print settings

• Orientation: printed as shown, studs up, the open underside faces the bed. A wide plate has to bridge that hollow underside, so beyond about 40 mm across, add supports under the top or print it upside down.
• Tiles: turn on Print upside down so the smooth top is against the bed and comes out glass-smooth.
• Layers and walls: a 0.4 mm nozzle, 0.12–0.2 mm layers and 1.2 mm walls (three perimeters). Fine layers give cleaner studs.
• Filament: PLA and PETG both work. Stiffer, less flexible filaments make a snappier fit; very soft ones grip less.

FAQ

Will these fit real bricks? They are drawn to the standard dimensions: an 8 mm stud spacing, a 9.6 mm brick height and a 4.8 mm stud. Whether a printed brick grips or slips depends on your printer, which is why the stud and side clearance are settings and there is a fit-test preset. Expect to adjust once, then keep the values.

Why does the part I searched for not appear? The list covers the plain bricks, plates and tiles. Slopes, curves, Technic bricks with holes, and printed or minifigure parts aren’t in it yet. If your part is a plain rectangle, set its size yourself.

Are the part numbers right? They are the design numbers used across the hobby, and each entry’s size and height was checked against the part’s published model. A few parts have lettered variants — 3023 and 3023b are the same plate — and either one finds it.

Can I edit it in CAD? Yes: the STEP button gives an exact model with true round studs and tubes, always the right way up, for Fusion, FreeCAD or Onshape.

Can I print hollow studs? Yes, choose Hollow studs. They are small holes, so use fine layers (0.12 mm) or the top of the hole may close over.

Why is the underside only 1 mm thick at the top? That matches a real brick and keeps the print quick. If you want a stronger brick, raise Wall thickness.

LEGO® is a trademark of the LEGO Group of companies which does not sponsor, authorize or endorse this site. “LEGO®-compatible” here only means the parts are made to fit bricks of that size.