PPI Calculator
Pixels per inch, dot pitch and total pixels from resolution and screen size.
The PPI Calculator computes pixel density — pixels per inch — from a screen's resolution and physical diagonal: 1920×1080 on a 24-inch monitor gives about 92 PPI, while a 6-inch 1080p phone is around 400 PPI.
PPI is the number behind 'sharpness': above roughly 300 PPI at phone distance the eye stops resolving individual pixels (Apple calls this Retina), while desktop monitors at arm's length look fine around 90–140 PPI. The tool also reports dot pitch (the physical distance between pixels) and total pixel count.
Everything derives from the diagonal formula PPI = √(w² + h²) ÷ diagonal — pure math running locally in your browser.
Pixel density (PPI)
91.8
pixels per inch
Dot pitch
0.277 mm
distance between pixels
Total pixels
2,073,600
2.1 megapixels
Screen diagonal
24.0″
2,202.91 px diagonal
For phones and laptops, ~300+ PPI looks sharp ('Retina' territory); desktop monitors are typically 90–140 PPI. Formula: PPI = √(w²+h²) ÷ diagonal.
How to use the PPI Calculator
- Enter the screen width in pixels.
- Enter the screen height in pixels.
- Enter the diagonal in inches.
- Read the PPI and dot pitch.
- Compare with the sharpness context given.
Frequently asked questions
What is a good PPI?
Phones need ~300+ PPI for a crisp look at reading distance; tablets ~260+; laptops ~150–250; desktop monitors 90–140 are standard and acceptable at arm's length. Higher is sharper until the eye cannot tell.
How is PPI calculated?
PPI = diagonal in pixels ÷ diagonal in inches, where the pixel diagonal is √(width² + height²). A 1920×1080 screen has 2,201 diagonal pixels — on 24 inches that is 91.8 PPI.
What is dot pitch?
The distance between pixel centers in millimeters — 25.4 ÷ PPI. Smaller dot pitch means finer pixels. It is the metric monitor spec sheets use alongside PPI.
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