How much house can I really afford?

One thing that Home Buying for Dummies stresses is that mortgage companies can only tell you how much they are willing to lend you, not how much you can actually afford. However, it was unclear to me how to figure that actual number out.

Then I remembered that my Personal Finance class has provided tools for calculating these sorts of things. Here are two useful ones for my situation:

Maximum Mortgage Payments for LDS - this one is nice because it is relatively simple and it takes into account tithes, offerings, and other donations. Just thirteen fields, all of which seem like something close to normal English (not Financese).

Home Loan Comparison with Prepayments Refinancing - I haven't really looked at this one yet, but it seems more complicated. It uses macros. However, I expect it to be useful when comparing mortgage offers.