REFERENCE / FORMATS
Eurorack and Kosmo panel dimensions: 3U, 1U, 2U, 4U
A 3U Eurorack panel is 128.50 mm high. 1U is 39.65 mm on the Intellijel standard and 43.18 mm on Pulp Logic tiles, which do not fit each other's cases. Kosmo panels are 200 mm high, in steps of 2.5 cm.
Every format at a glance
| FORMAT | HEIGHT (MM) | HOLE X (MM) | HOLE Y (MM) | WIDTH STEP | SOURCE |
|---|---|---|---|---|---|
| 1U Intellijel | 39.65 | 7.50 | 3.00 | 1 HP | Intellijel 1U technical specifications |
| 1U Pulp Logic tile | 43.18 | 5.08 | 3.00 | 6 HP | Pulp Logic 1U tiles |
| 2U row | 84.05 | 7.50 | 3.00 | 1 HP | Derived from the rack unit |
| 3U Eurorack | 128.50 | 7.50 | 3.00 | 1 HP | Doepfer A-100 construction details |
| 4U row | 172.95 | 7.50 | 3.00 | 1 HP | Derived from the rack unit |
| Kosmo | 200.00 | 3.00 | 3.00 | 25 mm | Look Mum No Computer, and the Kosmo community |
2U and 4U are not published by any brand. They take the rack unit (44.45 mm) multiplied out, less the 4.85 mm the rail lips take from a 3U panel, so a row built from the same rails fits.
Mounting holes
- The first column is 7.5 mm from the left edge; the others sit a whole number of HP from it, so they land on the 5.08 mm grid of the rails.
- Rows are 3 mm from the top and bottom edges.
- Panels wider than 10 HP take a column in between, and one always lands near the right edge.
- The default diameter is 3.4 mm, slightly over the 3.2 mm of the Doepfer drawing, so an M3 screw still passes through a 3D printed panel.
Kosmo panels leave the grid: see below.
Widths
Width is counted in HP, and a panel is cut a little under its pitch. The HP to mm table gives every width from 1 to 42 HP, and the HP and U calculator any other. Pulp Logic tiles are the exception: they come in multiples of 6 HP.
Kosmo
Kosmo is the large format started by Look Mum No Computer, with 1/4 in jacks and Eurorack power. It has no formal specification: these are the criteria its author publishes and the community's summary of them.
- Panels are 200 mm high and a multiple of 2.5 cm wide: 25, 50, 75, 100 mm and up, cut at the full width.
- Mounting holes sit 3 mm from the top and bottom and 3 mm from each side: one column per side, none in between. Metric widths leave the 5.08 mm grid of threaded rails, so Kosmo panels are held by sliding nuts or wood screws, anywhere along the rails.
- The rails take 10 mm at the top and at the bottom: keep components clear of them, with the clearance guides of the editor.
- The drill sizes page gives the holes of 1/4 in jacks.
Questions
How tall is a 3U Eurorack panel?
128.50 mm. A 3U rack row is 133.35 mm, and the rail lips take 4.85 mm of it.
Where do the mounting holes go on a Eurorack panel?
The first column sits 7.5 mm from the left edge, the rows 3 mm from the top and bottom, and every other column a whole number of HP from the first. The usual hole is 3.4 mm across, a little over the 3.2 mm of the Doepfer drawing so an M3 screw still passes through a 3D print.
How big is a Kosmo panel?
200 mm high, and a multiple of 2.5 cm wide (25, 50, 75, 100 mm and so on), cut at the full width. The mounting holes sit 3 mm from the top and bottom and 3 mm from each side, for M3 screws.
Sources
3U from the Doepfer A-100 construction details, 1U from the Intellijel 1U specifications and from Pulp Logic, Kosmo from the Look Mum No Computer criteria and the community specification. The editor applies them in panelFormat.ts.
Draw it instead of measuring it
Eurorack Panel Designer applies every number on this page automatically: pick a width in HP or millimeters, drop the parts, and export an STL, an SVG, a PNG or a KiCad Edge.Cuts outline. It runs in the browser, it is free, and it needs no account.
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