Defeasance Calculator - Helps you estimate the total cost to defease a loan, including the cost to purchase the defeasance collateral (government securities) and the transaction costs.

Mortgage Term Comparison Calculator - The Wall Street Journal's real estate website.

RE Buz Mortgage Calculator Tools - This extensive list of mortgage calculators includes mortgage payment, mortgage length, interest only, tax benefits, loan comparisons, APR calculators and buy vs. lease. There are also informative financing articles.

Yahoo Finance Calculators - Every kind of real estate calculator you could possibly need can be found here including whether or not to refinance, how much financing you can afford, "no-cost" vs. traditional mortgage, whether to pay extra points for a lower rate, reducing or foregoing expenses, return on investment and how much you should save to reach your goals.