Gridfinity dimensions: the 42 mm grid explained
Gridfinity is an open, modular storage system: a baseplate with a 42 mm grid and bins that drop into it in any combination. It is simple enough to design for yourself once you know a handful of numbers.
Short answer
Gridfinity uses a 42 × 42 mm grid. Bins are 41.5 mm per unit (0.5 mm smaller, for clearance), so an n-unit bin is 42n − 0.5 mm wide. Heights come in 7 mm units. Bases can hold 6 × 2 mm magnets and M3 screws. To fill a drawer, divide its inside width and depth by 42, round down, and use the leftover as a margin or a printed spacer.
Gridfinity turns a drawer of loose screwdrivers, bits and resistors into something that looks like a watchmaker’s tray. A printed baseplate lays a 42 mm grid across the drawer, and bins of any size drop into it and stay put. Designer Zack Freedman released it as an open system in 2022, and thousands of compatible bins have followed.
You can print other people’s bins, but the system is simple enough to design for yourself. These are the numbers you need.
The numbers
| What | Size |
|---|---|
| Grid pitch | 42 × 42 mm |
| One-unit bin, outside | 41.5 × 41.5 mm (0.5 mm clearance) |
| Height unit | 7 mm |
| Magnets | 6 mm diameter × 2 mm thick, round |
| Screws | M3, in the corners of the base |
| Base profile | A stepped, sloped foot about 4.65 mm tall that locates the bin in the baseplate |
bin width = 42 × units − 0.5 mm · bin height = 7 × height units
Bin sizes
| Units | Outside size |
|---|---|
| 1 × 1 | 41.5 × 41.5 mm |
| 1 × 2 | 41.5 × 83.5 mm |
| 2 × 2 | 83.5 × 83.5 mm |
| 2 × 3 | 83.5 × 125.5 mm |
| 3 × 3 | 125.5 × 125.5 mm |
| 2 × 4 | 83.5 × 167.5 mm |
| 4 × 4 | 167.5 × 167.5 mm |
Fitting a grid to your drawer
- Measure the inside width and depth of the drawer at the bottom, where the baseplate will sit.
- Divide each by 42 and round down. That is how many units fit.
- The leftover is margin: split it between both sides, or print a filler strip so the baseplate can’t slide.
A drawer 380 mm wide fits 9 units (378 mm) with 2 mm to spare. One 400 mm deep fits 9 units with 22 mm left, enough for a spacer strip at the back.
Fitting baseplates on your bed
Big drawers need more baseplate than fits on one print, so baseplates are printed in pieces that sit side by side. They don’t need glue or pins; the bins hold them in line.
| Printer | Bed | Fits |
|---|---|---|
| Bambu Lab A1 | 256 × 256 mm | 6 × 6 (252 mm) |
| Bambu Lab P1S | 256 × 256 mm | 6 × 6 (252 mm) |
| Bambu Lab A1 mini | 180 × 180 mm | 4 × 4 (168 mm) |
| Bambu Lab X1 Carbon | 256 × 256 mm | 6 × 6 (252 mm) |
| Bambu Lab H2D | 300 × 320 mm | 7 × 7 (294 mm) |
| Bambu Lab H2D Pro | 300 × 320 mm | 7 × 7 (294 mm) |
| Bambu Lab H2C | 300 × 320 mm | 7 × 7 (294 mm) |
| Bambu Lab H2S | 340 × 320 mm | 7 × 7 (294 mm) |
| Bambu Lab X2D | 235.5 × 256 mm | 5 × 5 (210 mm) |
| Bambu Lab P2S | 256 × 256 mm | 6 × 6 (252 mm) |
| Bambu Lab A2L | 330 × 320 mm | 7 × 7 (294 mm) |
| Bambu Lab P1P | 256 × 256 mm | 6 × 6 (252 mm) |
| Bambu Lab X1 | 256 × 256 mm | 6 × 6 (252 mm) |
| Bambu Lab X1E | 256 × 256 mm | 6 × 6 (252 mm) |
| Prusa MK4S | 250 × 210 mm | 4 × 4 (168 mm) |
| Prusa CORE One | 250 × 220 mm | 5 × 5 (210 mm) |
| Creality K1 / K1C | 220 × 220 mm | 5 × 5 (210 mm) |
| Creality Ender-3 V3 | 220 × 220 mm | 5 × 5 (210 mm) |
| Voron 2.4 (350) | 350 × 350 mm | 8 × 8 (336 mm) |
For more on dividing large prints, see the splitting guide.
Designing your own bins
- Start from the footprint. Pick the units and height, and let everything inside follow.
- Size cut-outs to the tool, plus clearance. A sliding fit of about 0.3–0.5 mm around a tool lets it drop in and lift out. The tolerance guide has the numbers; Loftsmith’s hex bit holder uses 0.4 mm over the bit’s 6.35 mm width.
- Walls of 1.2 mm or so are plenty for bins. See the wall thickness guide.
- Scoops and labels make bins nicer to use: a curved front inside for small parts, and a sloped tab on top for a label.
If you’d rather describe the bin than model it, Loftsmith can design one from a sentence, such as “a 2 × 3 Gridfinity bin for six 1/4 inch hex bits and a bit driver”, and hand you STL and 3MF.
Hex bit holderA bit holder with 0.4 mm of clearance over each 6.35 mm bit, a good starting point for tool cut-outs.94 × 28 × 15 mm · 17 g · 28 minQuestions people ask
What size is a Gridfinity unit?
42 × 42 mm on the grid, with a height unit of 7 mm. A one-unit bin measures 41.5 × 41.5 mm so it drops into the baseplate with a little clearance.
What magnets does Gridfinity use?
6 mm diameter × 2 mm thick round magnets, pressed into pockets in the bin base or baseplate. Many designs also include holes for M3 screws.
How many Gridfinity units fit on a Bambu Lab A1 mini?
Its 180 × 180 mm bed fits a 4 × 4 baseplate (168 mm) with room for a brim. The 256 mm bed of the A1, P1S and X1C fits 6 × 6 (252 mm), which is tight: many people print 5 × 5 for margin.
Who created Gridfinity?
Designer Zack Freedman, who released it as an open system in 2022. It has since grown a large community of compatible bins, baseplates and generators.
Sources and method
The numbers come from Loftsmith’s CAD engine, which uses them to design and check every part it builds, and from the manufacturer and reference sources below. Every figure is checked against those sources and the engine’s own geometry. Found a mistake? Email [email protected] and we’ll fix it.
