Practical tools for measured work
Pixels per Degree & PPI Calculator
Compare physical pixel density with angular pixels per degree for any resolution, diagonal and viewing distance.
PPI describes the panel itself. PPD includes viewing distance and horizontal field of view, so it is the more relevant angular-density comparison between different screen sizes and seats.
How it works
How to use it: enter native pixel dimensions, physical diagonal and eye-to-screen distance. Any aspect ratio is supported.
Formula. PPI = diagonal pixels / diagonal inches. PPD = horizontal pixels / horizontal viewing angle.
Example. A 65-inch 3840 by 2160 panel is about 67.8 PPI; its PPD changes when the seat moves.
Current-input example
The result above uses these exact values. This snapshot is included when the page is printed so the output can be checked against the original measurements.
- Screen diagonal
- 65 in
- Horizontal pixels
- 3840
- Vertical pixels
- 2160
- Viewing distance
- 96 in
- Reference PPD
- 60
Primary result: Pixels per degree: 116.8 PPD.
Before using the result
- Measure from the datum or reference edge described by this tool, and do not mix inside, outside and centerline dimensions.
- Keep inputs in the displayed units and preserve more precision than the final cutting or purchasing tolerance requires.
- When the result is close to a limit, verify it with a test piece, field measurement, manufacturer drawing or qualified project professional.
Limitations
PPD is a geometric density, not a complete image-quality score. eyesight, subpixel layout, scaling, antialiasing, contrast, motion and source quality matter. Nominal resolution may not equal resolved detail.
Frequently asked questions
Is 60 PPD always enough?
It is a common comparison reference, not a universal vision threshold. Content, eyesight and contrast affect whether more density is visible.
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