DPI / PPI Calculator

What it does

The DPI / PPI Calculator turns a display resolution into its pixel density and physical footprint: pixels-per-inch (PPI), dot pitch (millimeters per pixel), physical width/height in inches and millimeters, the diagonal size, and the reduced aspect ratio. Give it a diagonal or a known PPI and it solves for the other. Everything runs 100% client-side.

How to use it

1. Enter the Resolution - width × height in pixels (e.g. 1920 × 1080), or hit Sample.
2. Under Solve for the blank field, fill in Diagonal (in) or a known PPI - leave the one you want computed empty.
3. Read the result cards: PPI, dot pitch, aspect ratio, diagonal, and physical width/height (inches + mm) - each with its own Copy button.
4. Copy share link encodes your inputs in the URL so a teammate sees the exact view.

Examples

Full HD on a 24“ monitor

1920 × 1080, diagonal 24 in → ~92 ppi, dot pitch ~0.276 mm, aspect 16:9.

27“ QHD panel

2560 × 1440, diagonal 27 in → ~109 ppi, aspect 16:9.

Solve the diagonal from a known density

3840 × 2160, PPI 163 (leave diagonal blank) → diagonal ~27.0 in.

Good to know

• PPI vs DPI: PPI (pixels per inch) is the true digital density this tool computes; DPI (dots per inch) is a print term often used loosely for screens - they’re used interchangeably here.
• Dot pitch = 25.4 / ppi millimeters per pixel - smaller means a sharper display.
• Solve logic: if you enter both a diagonal and a PPI, the diagonal wins and PPI is recomputed from it.
• Shareable: resolution, diagonal, and PPI live in the URL (?w=…&h=…&d=…&ppi=…).
• Related tools: Subnet / CIDR Calculator, Number Base Converter.