Pixel Pitch Explained: P1.5 to P10

The "P" number on an LED display is the distance in millimetres between the centres of two neighbouring pixels. P4 means four millimetres. Smaller number, more pixels in the same area, sharper picture — and a sharply higher price.

The one rule that matters

Our viewing distance calculator at /viewing-distance-calculator/ turns that rule into an answer: give it the distance and it returns the coarsest pitch that still reads cleanly, plus the distance past which a finer pitch stops being worth paying for.

Three distances, usually quoted as one number

Before going further it is worth separating three things that the trade — and most spec sheets — run together under "viewing distance". They answer different questions, and only the first two are rules you should buy on.

The practical consequence is uncomfortable for anyone selling you a screen: past a certain distance you are paying for resolution almost nobody in front of the screen will separate. At ten metres, very few people will pick a P1.5 out from a P4 on ordinary signage content. If your screen is going above a shop shutter and read from across a footpath, a P4 is not a compromise — it is the correct answer, and the P1.5 quote is money burnt.

Pitch by environment and use

Pixel density, and why price rises so steeply

Pitch does not scale linearly with cost, because pixel count scales with the square of the pitch. Halving the pitch quadruples the number of LEDs in the same area — plus the driver ICs and the assembly labour that go with them.

This is why a P1.5 typically costs three to five times what a P4 costs for the same area, and why "just go one step finer" is never a small upgrade.

The specs that matter as much as pitch

Pitch dominates the conversation, but a badly specified P4 performs worse than a well specified P8. Ask for all of these in writing:

• Brightness — 800–1,500 nits indoor; 5,000+ outdoor, 8,000+ for direct sun. Under 4,000 nits can struggle badly in strong midday light, and how badly depends on orientation and exposure. Ask for 5,000+ regardless; it is the cheapest insurance on the quote.
• Ingress protection — confirmed for every side actually exposed to weather. IP65 front and rear is our standard for a cabinet fully in the open.
• Refresh rate — 1,920 Hz minimum, 3,840 Hz if the screen will be photographed or appear on camera. Below that, phone cameras commonly record dark rolling bands.
• LED chip brand — named on the quote. This is where much of the price difference between two similar-looking quotes actually sits.
• Cabinet — die-cast aluminium is lighter, flatter and more corrosion-resistant than iron, and easier to service.
• Panel life — 50,000 to 100,000 hours is the normal claim. Ask what the warranty actually covers, not just the claimed life.
• Control — asynchronous with a cloud CMS suits most shops; synchronous suits screens mirroring a live source.
• Serviceability — front or rear access. If the screen sits flush to a wall, front access is not optional.

Which is better, P2 or P3? And the other head-to-heads

Almost every real decision in India comes down to one of four comparisons, and the answer has the same shape each time: the finer pitch is better, and that is not the question. The question is whether anyone will stand close enough to tell.

Note what is missing from that table: any recommendation to go finer than the distance requires. Past the visual-acuity distance a finer pitch has almost nothing left to show the person standing there, so the only sensible answer is the coarser one — the viewing distance calculator at /viewing-distance-calculator/ gives that threshold for any distance.

The visual-acuity distance, and how to use it

This is the check to run when someone is pushing you upward — as long as you read it for what it is. An eye with good vision resolves detail down to about one arcminute, which works out at roughly 3.44 metres for every millimetre of pitch. That figure is geometry under ideal assumptions: high contrast, a sharp static edge, good eyesight, nothing else competing for attention. Real signage is none of those things. So treat the distances below as the point past which extra pixels stop earning their money, not as a line where the grid switches off:

• P2 — a finer pitch stops paying for itself past about 6.9 m
• P2.5 — past about 8.6 m
• P3 — past about 10.3 m
• P4 — past about 13.8 m
• P6 — past about 20.6 m
• P10 — past about 34.4 m

So a hoarding read from 35 m gains almost nothing visible from P4 over P10, at several times the cost. Buy the P10 and spend the difference on brightness and a structure that survives the monsoon. Overspending on pitch is the most expensive mistake in this category, and it is made by well-intentioned buyers trying to get the best screen they can afford.

The fitter’s shortcut, and where it stops working

Installers rarely carry a tape measure to the viewer. They use mounting height instead, because on a street the two are related — the higher the board, the further back you have to stand to read it comfortably. The shortcut runs like this:

It is worth knowing that this is a genuinely good shortcut rather than folklore. It agrees with the arcminute arithmetic above at ordinary shopfront heights, and it agrees for a physical reason: height forces distance, and distance is what actually sets the pitch.

The other place it misleads is indoors, where height and viewing distance are unrelated. A reception wall two metres above the floor is still read from two metres away, so it needs a fine pitch that the outdoor version of this rule would never suggest.

How to decide in two minutes

1. Stand where your customer will actually stand and measure the distance to the screen position.
2. That number in metres is roughly the coarsest pitch in millimetres you can use — the minimum practical distance rule, and a good first answer.
3. If you will show full video rather than text and stills, go one step finer.
4. If the site is outdoors, check brightness and IP rating before you spend anything more on pitch.