PPD calculator: pixels per degree from where you sit
Screen, seat, verdict
47.5 PPD · 60 PPD reference
The screen
How far you sit
How to measure your distance
With a tape measure, measure from your eyes to the centre of the screen.
Eye to screen. The tape measure below runs at true scale: stand the plate against the screen, step back to where your eyes are, read the mark.
OS scaling, if you use it
From that seat
Landscape orientation · Flat panel
At 64 cm, this screen has 47.5 pixels in the central degree of your view. It reaches the 60 PPD reference at 80 cm. This reference does not guarantee that pixels or resolution differences become invisible.
- Pixel density
- 109 PPI0.233 mm pitch
- 60 PPD distance
- 80 cmwhere it reaches 60 PPD
- Fills
- 50°of your view; a cinema seat is 40°
Make an installer plan · €9 PDF
Monitors from the same seat
Nearby monitors in the PPD ranking at your distance, highest central PPD first. The coral mark is yours.
| Screen | PPI | Central PPD | 60 PPD distance |
|---|---|---|---|
| DQHD 49" | 109 | 47.6 | 80 cm |
| QHD 27" 1000R | 109 | 47.5 | 80 cm |
| QHD 27" | 109 | 47.5 | 80 cm |
| 4K 42" OLED monitor | 106 | 46.3 | 82 cm |
| 4K 43" monitor | 104 | 45.2 | 84 cm |
Opens the size calculator with this screen and its viewing distance. Add another screen to compare dimensions and viewing angles.
Common questions
What is PPD (pixels per degree)?
PPD is how many pixels fit into one degree of your vision from where you sit. It combines pixel density with viewing distance: PPD = PPI × D × 2 tan(0.5°), with D the distance in inches, which is close to PPI × D / 57.3. The same panel gets sharper as you move back and softer as you lean in, and PPD is the number that tracks that.
What does the 60 PPD reference mean?
60 pixels per degree is a conventional reference associated with a one-arcminute detail size. It is not a pass/fail test for sharpness: eyesight, contrast, content, subpixel layout and rendering all affect visible detail. Higher PPD can offer diminishing returns without becoming universally indistinguishable. Cambridge's display-perception research measured higher limits for some patterns under controlled conditions.
How is central PPD calculated?
Central PPD = PPI × distance in inches × 2 × tan(0.5°). It counts the pixels in the central one-degree region for a head-on view. Whole-screen average PPD, calculated as horizontal pixels divided by horizontal field of view, is a different measure. Curved panels use their local central pixel density here; headset optics require a different model.
What is the difference between PPI and PPD?
PPI measures pixels per inch of panel. PPD also includes viewing distance. A 27-inch 2560 × 1440 monitor has about 109 PPI and 44.9 central PPD at 60 cm. The same screen reaches the 60 PPD reference at about 80 cm. Moving back raises PPD while making the picture occupy less of your view.
What does a 27-inch 4K monitor deliver at a desk?
A 27-inch 3840 × 2160 panel has about 163 PPI and 67.3 central PPD at 60 cm. It reaches the 60 PPD reference at about 54 cm. These figures describe angular sampling; they do not guarantee that a particular viewer cannot distinguish higher resolution. See 1440p versus 4K at 27 inches for a size comparison.
Does OS scaling change PPD?
No. Scaling changes interface size and workspace, not physical pixel density or viewing distance. A 27-inch 4K panel at 150% provides a 2560 × 1440 logical workspace while retaining its native pixels.
Can I use this for VR headsets?
This calculator assumes a direct view of a panel. Headset PPD depends on optics, distortion and position in the field of view, so screen diagonal and eye distance alone are insufficient.
Every number on this page is computed with the same formulas as the DisplayMath screen size calculator. Free, no signup, runs in your browser. Nothing you enter leaves the page. Updated 2026-09-09. Feedback? Email hello@displaymath.com or find us on Instagram. About · Privacy. © 2026 DisplayMath. All rights reserved.