About

Graphic designers and print specialists typically work across two conflicting domains: the physical world (millimeters) and the digital screen (pixels). Converting between them is not a fixed ratio; it depends entirely on the resolution density, measured in DPI (Dots Per Inch) or PPI (Pixels Per Inch). A 50mm box looks different on a low-res monitor compared to a high-density Retina display.

This tool calculates the exact pixel dimensions required to render a physical length at a specific density. It includes presets for common standards like Web (72 DPI) and Print (300 DPI) to eliminate guesswork. Accuracy here ensures that printed assets match their digital proofs without blurring or scaling artifacts.

Formulas

The inch is the bridge unit. Since 1 inch = 25.4 mm, we first convert millimeters to inches, then multiply by the density.

px = mm25.4 × DPI

Reference Data

Context	Density (DPI/PPI)	100mm in Pixels (px)
Legacy Web / Low-Res	72	283
Standard Windows System	96	378
High-Res Monitor	150	591
Standard Print (Draft)	150	591
High-Quality Print	300	1181
Apple Retina Display	326	1283
Commercial Press	600	2362
High-End Archival Print	1200	4724

Frequently Asked Questions

Historically, 72 DPI was standard. However, modern screens usually operate at 96 DPI or higher. For web usage, pixel dimensions matter more than the metadata DPI setting.

At 300 dots per inch, the human eye at standard reading distance cannot distinguish individual ink dots, creating the illusion of a continuous smooth image.

Mathematically, yes. However, raster images (JPEG, PNG) require whole integer pixels. This tool allows you to round to the nearest whole number for bitmap generation or keep decimals for vector (SVG) accuracy.

Yes. CSS defines 1 inch as exactly 96 pixels. If you set the DPI to 96, the result will match CSS unit definitions.