What tool are you using to create your artwork? There’s a somewhat long standing problem with Illustrator, which uses an different DPI which can cause things to resize.
If you are using Illustrator, try copy/pasting instead of saving as SVG.
Or, export as SVG, and make sure [ ] responsive is not checked.
Or, try PDFs
If all else fails, you can use the ruler in GFUI, and type “* 1.3333” after whatever is in there, and it’ll scale it up fixing for the difference in DPI that Illustrator has.
Here’s some discussion of the issue:
And you’ll find lots more searching these forums for things like, “sizing”, “resize”, etc
Good luck!