From Xojo Documentation

Read-Only Property (As Double )
DoubleValue = aDesktopDisplay.ScaleFactor

New in 2021r3

Supported on Desktop.

The ScaleFactor for the display.


A ScaleFactor of 1.0 indicates that each point refers to a single pixel on the display. Higher values indicate a HiDPI display of some kind is being used.

Sample Code

Var scale As Double = DesktopDisplay.DisplayAt(0).ScaleFactor