This repo and its contents are not official Nicks materials. For the latest, official word on sizing and fitting, see https://nicksboots.com/.
I put this repo together after seeing an old Nicks fitting chart shared in image form on Reddit a number of times. I wanted to verify that the measurement increments between length and width sizes were indeed linear---changing by a fixed amount between each size. I also wanted a table I could post into Reddit comment, which I did here.