Usage of the PNG output
For laser cutting a SVG file is needed. This software can also create a PNG file, why that is, is answered on this page.When you use a tool to view a SVG file, it often does not show dimentions. However if you open an SVG file in the laser cutting tool software, that might show a ruler, which reveals the size.
During development of this software I needed to verify if the drawings are correct. For that purpose I used PNG output with a DPI setting of my monitor, meaning I could measure a line on screen with a ruler.
How do you know the DPI settings of your monitor?
You could look it up in the manual, or maybe even faster, you measure it. Often the DPI figure in X direction is different when compared to the Y direction. This means the dots on your monitor are not perfect circles or squares, they are more like ovals.
Measure the width of the visible area of the monitor, for instance this is 61.2 cm.
Check the resolution: This is for instance 3840 x 2160 pixels.
DPI = 3840 / (61.2 / 2.54) = 157.06 Dots Per Inch ---> DPI in X direction is 157
DPI = 2160 / (34.1 / 2.54) = 160.89 Dots Per Inch ---> DPI in Y direction is 161
Fill in these numbers in the GUI of the tool and the generated PNG file should be 1:1 with the real size when you open that PNG file in for instance the 'Paint' application in Windows.