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

LibreCAD can't do a direct PDF to DWG converter on its own. It's a great, completely free 2D CAD program, but it doesn't have a magic "open PDF, save as DWG" button. It can import DWG files (though the support is basic) and it primarily works with its own main format, DXF. It can export to PDF, but going the other way isn't built-in.

So, how could you use it for this task? You'll need a two-step workaround. It's not a single PDF to DWG converter, but a process:

1. First, get your PDF into a DXF or SVG format. LibreCAD can import SVG images, but that's a dead-end for getting editable lines. The trick some people use is to convert the PDF to a BMP (or other image) first, then import that as a background image into LibreCAD and manually trace over it. It's a lot of work, but it's a free way to get a vector drawing out of a PDF.

2. Then, use LibreCAD to export as DWG. Once you have a DXF file (or have finished tracing), LibreCAD can open and save it as a DWG file. So, it handles the last step of the process, just not the first.

This is the big catch. If you convert a PDF to an image and trace it, keeping the original scale is all on you. You'd have to manually figure out the scale factor and adjust everything in LibreCAD. It's not automatic.