In a foreclosure situation, the bank may be required to determine the "Net Present Value" of your home.  Doing this math can help the lender know whether a loan modification would be in everyone's best interests.  The attachment below is the calculator the FDIC posted on its website until recently and the one that Maine mediators are still using to guide the lender and homeowner in the foreclosure mediation process.  This tool is difficult to use if you are not familiar with it.