If you have PPI (Pixels Per Inch), divide it by 25.4 (since there are 25.4 mm in an inch). Example: 300 PPI / 25.4 ≈ 11.81 pixels per mm.

In scientific software like or tpsDIG , users must set a "scale" to convert raw pixel counts into meaningful mm2m m squared data for measuring cell growth, bone density, or land area. 2. Roblox Murder Mystery 2 (MM2): The Pixel Knife Value Pixels to mm Converter (px to millimeters)