100mm in Illustrator 2015 is not 100mm on the monitor?

[LoveYou阿逗逼6666]

a rect width is 100mm

but the real with is not 100mm

Illustrator 2022 is right.

[Doug A Roberts · Accepted solution]

One of the CC versions after 2015 introduced the option 'Display Print Size at 100% Zoom' in Preferences > General. With this enabled, Illustrator will display real-world units at actual size on your monitor. With this option off, Illustrator will display 1 monitor pixel = 1 canvas pixel. Both modes have their uses.

[Ton Frederiks]

Illustrator has a Preferences option: "Display Print Size at 100% Zoom".

That may be not possible in 2015.

If so you need to find the zoom factor for the display to show the correct size.

[Doug A Roberts]

Added in CC 2019:

https://illustrator.uservoice.com/forums/333657-illustrator-desktop-feature-requests/suggestions/332...