How can I convert PDF to DWG with actual scale on my PC?

Best recommendation: The Ink scape + Manual Scaling Workflow:

This is the most reliable free method I've found, and it's been discussed by people using it for similar purposes like PCB design . The gist is that Ink scape can import a PDF and export a DXF, but the scale is often off. You have to correct it manually.

Here's how to convert PDF to DWG:

1. Import your PDF into Ink scape.
2. Prepare the drawing: Use Object -> Ungroup and Path -> Split to break the diagram down into individual, editable lines. This prevents weirdness in the final DXF file .
3. Find a known distance: This is the crucial part for scale. Look for a dimension line or any two points on the drawing where you know the real-world distance (e.g., a 100mm dimension marker).
4. Measure the on-screen distance: Use Ink scape's measuring tool to find the distance between those same two points on your imported drawing.
5. Calculate the scale factor: Divide the known distance by the measured distance. For example, if a line should be 100mm but measures 50mm in Ink scape, your scale factor is 2. Mul tiply that by 100 to get a percentage (200%).
6. Rescale the drawing: Select everything, set the toolbar units to "Percent," lock the aspect ratio, and type in your calculated percentage. Hit Enter, and your drawing should now be at the correct 1:1 scale.
7. Export as DXF: Go to File -> Save a Copy and choose the DXF format. Make sure to set the export units to "mm".
8. Import into your CAD software: Now you can import this DXF file into your CAD program. Remember to set the import units to "mm" as well.

This method works best if your are going to convert PDF to DWG. If your PDF is a scan or a raster image, Ink scape can't magically turn it into a DXF with editable lines—you'd be stuck tracing it manually.