Just wanted to say thanks for all the hard work. I also wanted to ask what formula you are using for max hp calculations/what lookup tables/values.
I've actually been implementing a similar calculator backend in python/c++ for fun, but using the formulas on http://irowiki.org/wiki/HP is currently giving me deviations in HP values for kagerous (I haven't had time to check against other classes). Using the irowiki formula with HP_JOB_A=0.75 and HP_JOB_B=5 for a level 101 Kagerou with 70 vit and +2 vit from job is giving me 7485 HP, which is 14 HP under the actual value. I also did that without factoring in the +2 job vit as I wasn't sure how it was factored in. Your calculator (which gives the correct values) gives 7412 for no job bonus and 7499 with job bonus (which is correct).
So yea, just wanted to know what formulas you are using/where you got the info from (unless it's entirely from tweaks from in game tests).
I'm also assuming that the lookup table linked in the irowiki page is no longer used, as it gives different values from irowiki page calculator and your calculator.
As an aside, is this/are you planning to make this open source?