The cabinet is the unit
A module is the sub-panel carrying the lamps. A cabinet is the enclosure built from modules, and it is the thing that appears on a price list, arrives on a pallet and hangs on a bracket. A wall is a whole number of cabinets — always.
That single constraint drives everything downstream. You cannot have a 4.55 m wall out of 600 mm cabinets; you can have 4.2 m or 4.8 m. Every sizing question in this trade is therefore really the question “which whole-cabinet grid gets closest to what I need?”
The formats you will meet
| Format | Ratio | Where it is used |
|---|---|---|
| 600 × 337.5 mm | 16:9 | Indoor fine pitch. The dominant format, and the reason modern pitches are odd numbers. |
| 600 × 300 mm | 2:1 | Fine pitch where a wall has to be long and low — above a lift lobby, behind a desk. |
| 640 × 480 mm | 4:3 | The older indoor standard. Still everywhere in retail and still being manufactured. |
| 500 × 500 mm | 1:1 | Rental and staging. Square cabinets rotate, curve and rig in standard bars. |
| 500 × 1000 mm | 1:2 | Rental, for building tall walls with half the frame count. |
| 960 × 960 mm | 1:1 | Outdoor. Big, heavy, sealed, and sized around the standard billboard grid. |
One product line now usually ships in several of these at once — a full cabinet, a half-height, and sometimes a narrow filler strip — with the expectation that a single wall will mix them.
Why 600 × 337.5 mm won
600 × 337.5 mm is exactly 16:9. That is the whole reason. It means a wall of any grid of these cabinets is 16:9 whenever the columns and rows are equal, and it means the pixel counts land on round numbers.
Divide 600 by a pitch chosen to give a clean pixel count and you get the odd-looking pitches the market now sells: 640 pixels gives 0.9375 mm, 480 gives 1.25 mm, 384 gives 1.5625 mm. The height divides equally cleanly: 337.5 ÷ 0.9375 is 360 pixels, exactly nine sixteenths of 640.
Six of the 0.9375 mm cabinets across and six high is 3 840 × 2 160 pixels — genuine UHD, on a wall that is exactly 16:9 at 3 600 × 2 025 mm. Nothing is approximate anywhere in that sentence, and that is the point of the format.
Tiling to a resolution
“I want a 4K wall” is now a more common brief than “I want a 5 m wall”, because a wall that maps one input pixel to one LED pixel needs no scaling, and scaling is where fine detail goes to die.
Work it in three steps:
- Pixels per cabinet = cabinet width ÷ pitch, and cabinet height ÷ pitch.
- Cabinets across = target width in pixels ÷ pixels per cabinet.
- If that is not a whole number, the cabinet cannot hit the resolution exactly — say so.
That last step is the one worth being honest about, and the failures are more interesting than the successes. A 1.5625 mm cabinet reaches 3 840 px in exactly ten columns, and 2 160 px in exactly ten rows. A 640 × 480 mm cabinet at 2.5 mm is 256 px across, so it also reaches 3 840 exactly — in fifteen columns — but it is only 192 px tall, and 2 160 needs 11.25 of those. That wall can be 4K wide and cannot be 4K tall. A 960 mm outdoor cabinet at 6.67 mm is 144 px across and would need 26.67 columns; it never reaches 4K width at all.
None of that is a fault in the products. It is a reason to check rather than assume, because a quotation that promises 4K on a cabinet that cannot deliver it will be found out at commissioning.
Half-heights and fillers
Real installations rarely land on a whole grid of full cabinets. Makers solve it with variants of the same product:
- Half-height cabinets — 600 × 168.75 mm against a 600 × 337.5 mm full cabinet — for when the opening is one and a half cabinets tall.
- Filler strips, narrow cabinets used to close a gap at one edge, usually with the same pitch and a reduced module count.
- Corner and curve kits for wrapping a column or turning an inside corner.
These carry different prices, weights and power figures, so a quote that mixes them cannot be written as one quantity × one unit price. That is the practical argument for a catalogue that models variants rather than a spreadsheet with one row per product.
Fitting a real opening
When you have a site measurement, there are three defensible ways to land on a grid, and the choice should be explicit rather than accidental:
- Inside. Round down. The wall never exceeds the opening. This is the safe default when you are quoting against a builder’s drawing you did not produce.
- Nearest. Round to the closest whole cabinet. Fine when the opening is a guide rather than a constraint.
- Cover. Round up. Correct when the wall must fill the aperture and the surround will be built to it.
Leave room for the frame, the service access and the tolerance of the opening itself. A wall sized to the millimetre of a drawing will not fit a wall built to ±10 mm.
A sizing checklist
- Confirm the cabinet format and pitch from the supplier data sheet, not from memory.
- Decide whether the brief is a size, an opening, or a resolution — they lead to different grids.
- Land on whole cabinets, and record which rounding you used.
- Check the true ratio of the wall as built, not the one you were aiming for.
- Check the resolution is exact if you promised it, and say so plainly on the offer if it is not.
- Carry the cabinet count into weight, power and receiving cards — the figures other trades need.
The configurator does all six, including telling you when a resolution is not reachable, which is the step most tools quietly skip.