This is what I do to draw from an existing drawing, regardless of file type. I 1st covert the drawing to a picture image (e.g. jpg or png). Import the image into my plan. Then draw one exterior wall to the known specified dimension. Then I resize the jpg (using the image handle) to match the wall I drew to get to the right scale. Once you sized the jpg to the right scale, you can just trace the rest of the drawing (and place fixtures) without any calculations/measurements.
The sizing of the jpg will never be exact - but I suspect you're just trying to visualize your build in 3D - for that purpose, it's accurate enough.
An extra step, if you choose, is to use an image editor (or just Power Point) to set the background color of your drawing to transparent. That way, when you draw over it, you can still see the dimension grids.
Attached is an example of a drawing image (in png) that you can import to your plan for tracing.
Teric
HD Pro 2017
Intel Sandy Bridge i5
16 GB RAM
Nvidia G-Force GTX 660 2GB