I've uploaded a webpage I wrote a couple of years ago.
It lets you interactively choose bit size / bush size / template size for bush routing with a hand held router.
Works with circles and rectangles.
https://inkscape.org/~bipper/%E2%98%85router-circles-and-rectangles
Using Inkscape with Cutters/Plotters Old School Wood Routing Templates
Inkscape.org
I've uploaded a webpage I wrote a couple of years ago.
It lets you interactively choose bit size / bush size / template size for bush routing with a hand held router.
Works with circles and rectangles.
https://inkscape.org/~bipper/%E2%98%85router-circles-and-rectangles