Somewhere on that chart you should find a note indicating that they are using a 1:1 ratio for the gears.

https://www.jk-forum.com/forums/show...276#post211276


Some quick numbers - using 31" actual height for the stock 32's, and 34" actual height for 35's. These are for 6th gear, not the 5th gear your chart is showing.

3.73, 31" = 2378 rpm @ 70
4.10, 31" = 2614 (stock 6spd Rubicon)
4.10, 34" = 2384
4.56, 34" = 2651
4.88, 34" = 2837
5.13, 34" = 2982


Assuming I didn't misplace a number here or there, of course.