How to Calculate Screen PPI
What is Screen PPI?
Pixels Per Inch (PPI) — also called pixel density — measures how many pixels fit into one linear inch of a display. Higher PPI means sharper images. Apple introduced the term 'Retina Display' for screens with PPI high enough that individual pixels are not distinguishable at a typical viewing distance (generally ≥ 200–300 PPI depending on screen size and viewing distance).
Formula
Step-by-Step Guide
- 1Diagonal pixel count = √(width² + height²) in pixels
- 2PPI = diagonal pixel count / diagonal screen size in inches
- 3Dot pitch = 25.4 mm / PPI — physical size of one pixel
- 4Total megapixels = (width × height) / 1,000,000
Worked Examples
Frequently Asked Questions
What is Screen Ppi?
Pixels Per Inch (PPI) — also called pixel density — measures how many pixels fit into one linear inch of a display. Higher PPI means sharper images
How accurate is the Screen Ppi calculator?
The calculator uses the standard published formula for screen ppi. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.
What units does the Screen Ppi calculator use?
This calculator works with inches. You can enter values in the units shown — the calculator handles all conversions internally.
What formula does the Screen Ppi calculator use?
The core formula is: Diagonal pixel count = √(width² + height²) in pixels. Each step in the calculation is shown so you can verify the result manually.
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