The number on the quote is not the number that matters
P2.5 does not mean anything until you put a tape measure on the floor. The same cabinet looks crisp at four metres and looks like a checkered tablecloth at one metre. What decides it is the angle your eye subtends on a single pixel, and that is set by pitch divided by distance.
Three rooms, three answers
| Room | Closest viewer | Pitch that holds up | Why |
|---|---|---|---|
| Boardroom, 6 m deep | 2.2 m | P1.5 – P1.8 | People lean forward to read a spreadsheet |
| Retail lobby, 12 m deep | 3.5 m | P2.5 | Nobody stops closer than the reception desk |
| Outdoor plaza, 30 m | 8 m | P4 – P6 | Text is 200 mm tall, not 20 mm |
Where the formula breaks
It assumes the content is authored at native resolution. If your player is upscaling a 1080p slide deck onto a 4K wall, the effective resolution is 1080p and the pitch calculation is meaningless. I have seen a P1.2 wall look worse than a P2.5 wall for exactly this reason. Check the source before you check the pitch.
What I would put on the enquiry
Write down the closest seat, the farthest seat, and the smallest text height you need people to read. Those three numbers turn a pitch argument into a specification. Anything else is a supplier guessing on your behalf.