Created by Jack M. Guttentag, a Professor of Finance Emeritus at the Wharton School of the University of Pennsylvania, it contains a host of really useful calculators such as mortgage calculators, down payment calculators, APR calculators and so much more.

Take a look.  Of course, nothing in this life is guaranteed (death and taxes excluded), not even the accuracy of online calculators, so be sure to “check the facts” by consulting with a mortgage broker or your accountant before you make any life altering decisions.