While job hunting, I wanted a way to compare offers that could take different cost of living and tax rates into account. Hacked this thing up. It has hardcoded 2015 tax brackets pulled from tax-brackets.org - it is not super accurate but should give a kind of rough idea of how salaries actually compare.
I assume the user is single and has no dependants or other investments. Things are a little messier when those assumptions go away.
This will save your session locally, but does not send any data to a server (in fact, davidbstein.com is a static stite)