How to calculate LED wall size and cabinet layout

LED walls are not projector screens. You cannot trim an inch off the side. Cabinets lock you into a grid: so many columns, so many rows, each with a fixed pixel map. If you skip the grid math, you discover on site that the wall is 192 mm too wide for the proscenium, or that 1080p content is 140 pixels wider than the processor canvas.

This guide shows how to convert a target size and pitch into cabinet counts, native resolution, and a layout you can send to the rigger, the electrician, and the content team.

Gather the four numbers you cannot invent later

Before opening a spreadsheet, write down:

1. Pixel pitch in millimeters (from the pitch tutorial).
2. Cabinet size — commonly 500×500 mm, 500×1000 mm, 640×480 mm, or 1000×250 mm. Use the actual mechanical drawing, not a rounded marketing size.
3. Target aspect — 16:9 for most worship and corporate playback; 2.35:1 or custom for scenic; 9:16 for columns.
4. Maximum physical envelope — opening width, trim height, ground-stack height, motor points, and door/elevator limits.

Also note module size inside the cabinet (often 250×250 mm). You rarely hang by the module, but you do service by the module, and some odd aspect walls are easier if you can drop a column of half-cabinets.

Compute pixels per cabinet, then per wall

For a rectangular cabinet:

pixels across = cabinet width (mm) ÷ pitch (mm)
pixels down = cabinet height (mm) ÷ pitch (mm)

Example: 500×500 mm P2.6 cabinet.

• 500 ÷ 2.6 ≈ 192.3 — real products use an integer pixel map, often 192×192 for “P2.6” on a 500 mm cabinet. Always use the manufacturer’s pixel map, not the raw division, when you order.

If the drawing says 192×192, trust that. Then:

wall pixels X = columns × cabinet pixels X
wall pixels Y = rows × cabinet pixels Y
wall width = columns × cabinet width
wall height = rows × cabinet height

Example: 8 columns × 4.5 rows is not legal if you only have 500 mm cabinets. You can do 8×4 (4.0 m × 2.0 m) or 8×5 (4.0 m × 2.5 m). Half-height 500×1000 cabinets turned as 1000×500 change the grid. Decide the cabinet SKU first.

Work a full 16:9 example.

You want a wall about 6 m wide in P2.9 with 500×500 mm cabinets that are 168×168 pixels.

• 6.0 m ÷ 0.5 m = 12 columns.
• 16:9 height = 6.0 × 9/16 = 3.375 m → 3.375 ÷ 0.5 = 6.75 rows. Not an integer.
• Choices: 12×6 = 6.0 × 3.0 m (slightly short of 16:9), 12×7 = 6.0 × 3.5 m (slightly tall), or mix 500×1000 cabinets to hit 3.375 m if the product line allows it.

Native resolution for 12×6 of 168×168 cabinets: 2016×1008. That is a comfortable 1080p-class width with a slightly short height. Content can be 2016×1008 native, or 1920×1080 with small bars or a crop. Tell the ProPresenter operator the native size, not “it’s 1080p.”

Choose a canvas strategy

There are three honest ways to relate content to the wall.

Native canvas. Build every look at wall pixels. Sharpest result. Requires templates for that exact grid. Best for a house wall that never changes size.

Standard 16:9 with letterbox or crop. Keep 1920×1080 or 3840×2160 show files. The processor scales or the operator builds safe areas. Easier for guest presenters. You will lose either pixels or picture.

Multiple surfaces. Center IMAG at one resolution, side scenic at another. The processor has two layers or two outputs. Do not pretend they are one 16:9 rectangle unless you like warped lyrics.

Write the chosen strategy on the plot. “Looks like 16:9 from the seats” is not the same as “is 1920×1080.”

Plan the cabinet map the rigger and the mapper will share

Draw columns left to right as seen from the audience, and rows from top to bottom or bottom to top — and pick one convention and keep it. Receiving-card software, the rigger’s elevation, and the power plot must use the same origin.

Typical notes on a one-page layout:

• Cabinet ID grid (A1 top-left through the last column).
• Data direction (which cabinet is the first in each RJ45 or fiber chain).
• Power injection points and which cabinets share a circuit.
• Up-arrow / handle orientation.
• Any missing corners, arches, or notched columns around a baptismal or proscenium.

If you are building an arch or a cross, you are still assembling rectangles. Count every cabinet, including the ones that create the void. Order spares as a percentage of installed cabinets, not of the pretty outline.

For touring or church-in-a-box systems, standardize on one grid (for example 8×4 of 500 mm) so every weekend’s content and every spare module stays interchangeable.

Check mechanical and access constraints

A mathematically perfect 16×9 grid still fails if:

• Cabinets do not fit through the sanctuary door in their flight cases.
• The truss is 40 feet and the wall is 41 feet including side frames and safety steels.
• Ground-stack height exceeds the base-plate rating or the venue’s fall-protection plan.
• The wall sits in front of a sprinkler, exit sign, or projector throw you forgot.

Add the frame, dollies, and hanging hardware to the width. A 6.0 m LED face can become 6.3 m once you add end frames and bumper. The rigger’s load includes cabinets, frames, motors, and cable pick-ups — not just the LED square-meter weight from a spec sheet.

Leave a service aisle or a plan to unhook a column. Fine-pitch indoor cabinets are often serviced from the front; outdoor and some rental cabinets from the rear. Rear service needs 60–100 cm behind the wall. If the wall is hard against drywall, you just bought a front-service product whether you meant to or not.

Power and data follow the same grid

Cabinet layout is also electrical layout. Group cabinets so that a single 20 A circuit is not asked to start an entire 8×6 wall. Note inrush (often 1.5–2× running watts on cheap PSUs). See the power-and-cable tutorial for the math; the point here is to draw circuits on the same grid as the pixel map.

Data chains usually run down a column or across a row, 6–16 cabinets per output depending on resolution and the sending card. A 12×6 wall might be four data lines of 18 cabinets, or six lines of 12. Shorter chains boot faster and fail more gracefully. Label both ends of every Cat cable with the column and port number that match the map.

Worked example: church IMAG wall

• Pitch: P2.6, 500×500 mm, 192×192 px.
• Opening: 20 ft wide, 12 ft to the lighting pipe.
• Target: 16:9 IMAG plus lyrics.

20 ft is 6.10 m → 12 cabinets = 6.00 m, which fits with 5 cm to spare per side if the opening is clean. Height for 16:9 would be 3.375 m → 6.75 cabinets. Choose 12×6 = 6.00 × 3.00 m (2016×1152 px) and accept a slightly wider-than-16:9 wall, or 12×7 = 6.00 × 3.50 m (2016×1344) if the pipe allows it.

2016×1152 is an excellent ProPresenter canvas. Build the house template at 2016×1152. Export guest 1080p into a 1920×1080 layer centered on that canvas.

Order 74 cabinets if you want two hot spares (72 installed + 2). Store the spares in the same firmware and receiving-card configuration as the wall.

Common mistakes

Rounding pitch math. “P2.6 on 500 mm is about 192” must become the actual 192 or 196 from the datasheet. One pixel per cabinet times 80 cabinets is an 80-pixel surprise.

Designing in feet and buying in millimeters. Convert once, then stay metric on the grid.

Forgetting that 16:9 is a ratio, not a cabinet count. You will almost always be one row off. Choose the compromise on purpose.

One giant data chain. It works in the shop and flakes on a 30 m run with a cheap switch.

No spare column. A dead cabinet in a 1-wide decorative fin has nowhere to hide. Buy the spare with the job.

Content team never gets the pixel map. They will send 1920×1080 with a 64-pixel logo in the corner that lands on a cabinet seam or off the wall.

Checklist before you order

• Pitch and cabinet pixel map confirmed from the datasheet
• Columns × rows chosen as integers
• Physical width/height including frames
• Native resolution written for playback
• Canvas strategy agreed (native vs 16:9 vs multi-surface)
• Data ports and power circuits sketched on the same grid
• Service access and door/elevator path confirmed
• Spare cabinets and modules on the PO
• Rigger and electrician have the same drawing

When those boxes are checked, hanging the wall is still work — but it is no longer a geometry puzzle.