Is your code Imperial G20 or Metric G21?
The moves themselves are just numbers, the presence of G20 or G21 tells the controller whether 1.5 is 1.5 inches or 1.5 centimetres.
Likewise your CAD/CAM can be set to Inch or Metric so both your CAD/CAM and the controller need to be working in the same units.
Once you get that sorted out you need to sort out your motor step settings in the controller such that a G-Code command to move a given distance actually results in a move of that distance.
It all seems complicated but it really isn't once you get into it ;-)