Ring Size System Conversion

Spreadsheet based tool to help convert between the various ring size system (e.g. US+Can, UK+IE+AUS+NZ, IND+CHN, Swiss)and allow you to calculate the ring internal diameter in mm. Also gives linear best fit equations based on data found here http://en.wikipedia.org/wiki/Ring_size

Potentially very useful when combined with the following:
Ring Creation Script thingiverse.com/thing:12448
Diamond size shape weight conversion Spreadsheet thingiverse.com/thing:12586
Ring metal cost calculator th