A "how much house can you afford" calculator, would be for consumer suckas, I don't think MMM would ever speak positively of something like this, much less develop one.
You should instead, first decide if you really want a house or if you'd rather rent, here are some related articles,
http://jlcollinsnh.com/2013/05/29/why-your-house-is-a-terrible-investment/http://jlcollinsnh.com/2012/02/23/rent-v-owning-your-home-opportunity-cost-and-running-some-numbers/http://www.mrmoneymustache.com/2015/07/27/rent-vs-buy/http://jlcollinsnh.com/2015/09/23/case-study-14-to-dream-the-impossible-dream-and-then-realize-it/That last one isn't completely relevant, but is a recent case study on someone who regrets buying houses.
After deciding you're sure you do want a house,
deciding your job is stable and you don't plan on changing very much for the next decade,
deciding you'll either live in it long enough to make the expense and HUGE annoyance of house buying worthwhile, or rent it out afterwards(which could affect a future house purchase),
deciding that you're okay being liable for maintaining your home and paying all the exorbitant fees that go along with owning your own home,
and deciding that you're okay not having the flexibility of those who rent
You should then figure out how much house you really need.
I'm not sure where I read it as I can't find the exact article, but Mad Fientist(another financial blogger) did an experiment to see how much stuff actually made his life better, rather than just asking himself if X makes his life better, he started getting rid of things and seeing if it made his life any worse. I think if you could somehow do an experiment similar to this, but with housing instead of items, to see how much house you actually need, it would be very beneficial. Also if there are things you know will change in the future making you need a different house, you should consider
1) renting a place that will meet your needs until then, and then buy, or
2) buy a house that will meet current needs as well as future needs.
Good Luck!