Why don't the dimensions in CorelDraw match the physical dimensions on the screen?

Question

Design

Greetings. There was such a "mysticism" with Corel Draw x6: when you specify the image size, as on the screen, let's say 90mm x 90mm, when measuring with a real ruler, the actual size is 8.5cm, where does 5mm go?
On another PC with the same version of Corel Draw, everything is the same, I tried to reset the settings, reinstall, install a different version - nothing changes. Please help, what could be causing this problem? How to fix it? It's just that printing requires exact dimensions, and so you have to add an extra 5mm to the desired dimensions

Answer 1

What is the resolution of pixels per inch (dpi DotsPerInch) in your settings - 75 dpi? Do you have a 100 dpi monitor? To match, you need to set the same.

Answer 2

Tools - Options... - Workspace - toolbar - Scale, Hand... - Calibration of rulers
Apply a ruler to the screen and calibrate
Turn on the "Related to 1:1 scale"
checkbox And don't bother with any screen resolutions

Answer 3

As described above, this is due to a mismatch between the resolution on the monitor and the settings in Corel. Somehow I changed these parameters in Photoshop and then you can adjust the dimensions 1 to 1 by pressing one button, but is this necessary?