Display Density Reference
Common sizes and resolutions worked out, so you can see where a panel lands before ordering it.
BFCBrilliance · bfcbrilliance.com/tools/ppi-calculator
The screen you are considering
- Model
- Diagonal
- Resolution
- PPI
- Actual width
- Actual height
- Aspect ratio
- Desk space available
Compare candidates
| Model | Size | Resolution | PPI | Width | Verdict |
|---|---|---|---|---|---|
The arithmetic
- Diagonal pixels
- square root of (h² + v²)
- PPI
- diagonal pixels / diagonal inches
- Actual width
- diagonal x h / diagonal pixels
- Dot pitch (mm)
- 25.4 / PPI — SMALLER is sharper
- Assumes
- square pixels, flat rectangular panel
- Not modelled
- viewing distance, subpixel layout
Where common screens land
- 24in 1920x1080
- about 92 PPI
- 27in 1920x1080
- about 82 PPI — noticeably soft
- 27in 2560x1440
- about 109 PPI
- 32in 2560x1440
- about 92 PPI
- 27in 3840x2160
- about 163 PPI
- 32in 3840x2160
- about 138 PPI
- 43in 3840x2160
- about 102 PPI — LESS than 27in 1440p
- 55in 4K television
- about 80 PPI — fine from the sofa
Before buying a screen
- PPI worked out - not just the resolution on the box
- Actual WIDTH checked against the desk, not the diagonal
- Viewing distance considered - it matters as much as density
- Scaling expected on a high-PPI panel: sharper, not more workspace
- Graphics card checked against the megapixel count if you game
- Stand height and depth allowed for beyond the panel dimensions
- Refresh rate and panel type considered separately - PPI is only sharpness
Resolution is a pixel count, not a sharpness
A 43 inch 4K panel is LESS dense than a 27 inch 1440p one — 102 PPI against 109 — despite having more than twice the pixels. What you see is how thinly the pixels are spread, and the number on the box does not say. Work out the density before believing the marketing.
Distance does as much work as density
A 55 inch 4K television is about 80 PPI and looks flawless from three metres. Put the same panel on a desk and it is unusable. Nothing about the screen changed — only how far your eye is from it, which is the variable no specification sheet contains and no calculator can guess.