User blog comment:FairyTailFan7/Sting's Attacks Are Light Speed?/@comment-26715029-20150820131706/@comment-7418318-20150820132138

I pity that person for wasting so much time on this.

All those calculations are based off of two assumptions:
 * 1) That Hiro Mashima is 100% accurate and consistant in all the factors it's based off... which simply is not the case.
 * 2) That the Fairy Tail world has the same laws of physics (as we do, which we have no way of knowing) and that magic can't curcumvent them.

And thus all the calculations become pretty much meaningless and thus a waste of time.

As was your effort in digging it up and posting it here I'm afraid.