I am always interested in how to pay off loans faster.
"How would it affect my loan if I make an extra payment?"
This question is answered down to the approximate penny with this amortization schedule calculator. All you have to do is download the spreadsheet (there are no macros) and enter in the initial loan amount, interest rate, loan term (in years), and first payment date and you will be presented with a schedule that separates exactly how much money you'll be expecting to spend on interest vs. principle from the loan origination date through the last payment of the loan.
If you have questions on how to use this spreadsheet, please post a question and I'll work on getting it answered as soon as possible!
Note: This spreadsheet is protected so that you only edit the cells that are meant to be edited. If you are an advanced finance person and would like to edit this spreadsheet's formulas, the password is given on the spreadsheet itself.
Download [download id="1"]