The calculator numbers don't really work with these because the they are such outliers. The superfat at 20% basically balances out the stripping effect of all the CO. I don't know if salt bars are great for the skin per se, I think people like them for the lather and maybe the exfoliation? Personally I prefer brine bars, aka soleseife if you are googling (less salt, lower CO and lower SF). I think it is a very individual thing.