Work out pixel density (PPI) from resolution and screen diagonal - with dot pitch and megapixels. Locally, no upload, in your browser.
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
Pixel density (PPI, pixels per inch) tells you how finely a screen resolves: the more pixels fall on a given length, the sharper and less grainy the image looks. It follows from the resolution (pixels in width and height) and the screen diagonal in inches: the diagonal in pixels (via the Pythagorean theorem) divided by the diagonal in inches. For comparison: desktop monitors are often around 90 to 110 PPI, print usually needs 300 PPI, and modern smartphones reach 400 PPI and more.
The calculation runs entirely locally in your browser, in pure JavaScript - nothing is uploaded and nothing is stored. From the width, height and diagonal the calculator works out the pixel density in PPI, the dot pitch in millimetres (the distance between two pixel centres, 25.4 divided by the PPI) and the total resolution in megapixels. A smaller dot pitch means a sharper image. Change any input and everything updates instantly.
An honest note: the calculator assumes a uniform, rectangular pixel grid and uses the screen diagonal in inches - the international convention for display sizes. The dot pitch is the theoretical distance between pixel centres; the actual subpixel layout (such as RGB stripes or PenTile) is not considered. PPI and DPI are often used interchangeably in everyday use; strictly, PPI refers to a screen and DPI to print.
| Input formats | Form inputs (no file) |
|---|---|
| Processing | Locally in your browser (JavaScript) |
| File upload | None |
Limitations: A pure calculation helper: PPI = diagonal in pixels divided by diagonal in inches; dot pitch = 25.4 divided by PPI (mm); megapixels = width times height. Assumes a rectangular pixel grid; subpixel layout and panel technology are not considered. Diagonal in inches (display convention).
No. The calculation runs entirely locally in the browser (pure JavaScript); nothing is sent or stored.
PPI (pixels per inch) describes screens, DPI (dots per inch) describes print. In everyday use the terms are often used interchangeably.
Desktop monitors are often 90 to 110 PPI, print usually needs about 300 PPI, and smartphones reach 400 PPI and more.
The distance between two adjacent pixel centres in millimetres. A smaller dot pitch means a finer, sharper image.