Q: I need a good calculator program to be able to enter in a loan from 2008 where I paid different amounts of extra principal along the way and would like to be able to see the amortization schedule. I want to rerun it every month as I pay different amounts of extra principal. I don't mind keying in everything, as long as it's only one time per transaction. Any suggestions?
A: Our downloadable (windows-based) Homebuyer's Calculator Suite will do irregular amortization, but as you note, it is a slow process.
You can download the calculator and install it on a local machine. Run the calculator, and refer to our tips page to find out how to input the irregular prepayments you describe.
However, the mortgage calculator does not have a "save" feature, so you would need to re-do all the calculations each time you make an additional prepayment.
Microsoft Excel does have a mortgage payment/amortization function, and what you want can be built for you, but you'll need someone who is adept at Excel. Alternately, you might search on the Internet to see if someone has a shareware/freeware version you can obtain.