DXF file mm and inch

Hello people,

I downloaded LibreCad and I find it very good for my needs.
Im using version 2.1.3.
I have plasma and cnc table from PlasmaCam which is from USA and it has inch as main measure type.
Now my problem is that Im from Croatia and I make drawings in mm.
When I import this DXF file into the PlasmaCam software my drawing is not in original measure, it is huge.
Do you have any suggestion what to do to avoid this problem?

Thanks for answer.

First I would look if the PlasmaCam software really can't accept mm. Even if it's from USA I would be surprised. I would expect there is a possibility to switch to mm somewhere.
If not, 1 inch is 25.4 mm. So you have to scale down the drawing in LibreCAD. Tools - Modify - Scale, in the input box write "1/25.4" for the scaling factor. Just to change the units to inch is not enough, the drawing is not being scaled automatically.  

Thank you for answer.
Tomorrow morning I will test this and post results.