Screen resolution calculator
Enter a resolution and a diagonal size to get pixel density, aspect ratio and total pixels — plus a reading of what your current display reports.
Density only tells half the story — viewing distance is the other half. A phone at 460 PPI and a billboard at 10 PPI can both look perfectly sharp.
How to use it
- Enter width and height in pixels.
- Enter the diagonal in inches.
- Read off PPI and ratio.
Questions
What PPI counts as a high-DPI display?
Roughly 200 PPI and up for laptops and phones held close, where the operating system will typically render at 2×. Desktop monitors at normal viewing distance look sharp from about 140 PPI. It depends on distance as much as density — a billboard at 10 PPI looks fine from across the street.
Why does my screenshot have more pixels than my screen resolution?
Because you are on a high-DPI display. macOS reports a 1440-point-wide window but captures 2880 real pixels. That is a feature — those screenshots stay sharp when scaled — but it is why they are larger files than you expect.
Related tools
This is one keystroke inside LayerShot
The desktop app captures the screen, applies your styling and puts the result on your clipboard without a browser tab, an upload, or a download folder full of files called Screenshot (3).png. One payment, one Mac and one Windows PC, lifetime updates.