Program Bugs

Rather than a feature, if you notice some behavior of the calculator that isn’t what you expect or values that you believe to be incorrect, make a note of such things by adding comments to this page. You’ll need to create an account for yourself (if you haven’t already).

27 Replies to “Program Bugs”

  1. Hi Bret,

    I enjoy using your Amortization Calculator probably far too much. The past few weeks I haven’t been able to use the “Show Amortization Schedule” box. Or rather, I mark the box and I am not receiving the schedule.

    Just letting you know and also, thank you!

  2. Hi Bret,

    Just wanted to ask if there is an archived version of this calculator somewhere. The updated version gives me some unexpected responses.

    I need to be able to calculate the annual interest rate. So, I put 40000 as the principal, 12 payments per year, 144 regular payments, and 400 as the payment amount. I leave balloon payment and annual interest rate blank. The calculator changes the regular payments to 100 and sets the annual interest rate at 0.

    Help please!

    1. Hi, Jeff. I do not have an archived version of the calculator. However, I cannot duplicate the problem that you have described. The calculator does the right thing given the input fields you provided. I’m taking a wild guess, but maybe there’s a residual value being passed along from your browser. You might try shutting down the browser and starting up a fresh copy of it and try again.

      If you continue to experience this problem, please write back with some more information about your browser and operating system.


  3. Bret,
    can I calculate an interest only loan paying interest plus some extra to principal? it is a 30 year am with interst only for 10 yrs. I want to see what the balance would be after 10 years with the extra monthly payment.

    1. You can do this calculation in pieces. First, run the calculation as a regular 30-year mortgage, and have the calculator determine what the payment should be. In the “Summary” section, make note of what the “Interest Only” payment is. Now enter this amount in the “Payment Amount” field, plus whatever extra you want to add. Set the “Number of Regular Payments” to 120 (for 10 years), be sure the “Show Amortization Schedule” box is checked, and click “Calculate”.

      The “Balloon Payment” field will now contain the expected principal payment *plus* another period’s interest payment. If you scroll down the amortization schedule to line 120, you’ll see the remaining principal in the far-right column. Now you can use the remaining principal to do a fresh 20-year amortization, if you’d like.


  4. Hi, Bob. Printing is really a browser function, and try as I might, I haven’t been able to get my browser to duplicate the blank pages you’ve described. Still, I’ve tweaked the printing CSS further just in case. Can you try a different browser to see if it does the same thing? (Neither Firefox nor IE8 under Windows7-64 produce blank pages for me with the current calculator output.)


  5. Hi Bret,

    When I print an amortization it always adds 3 additional pages of blank sheets. I have tried to limit the page to “1 of 1” but it still prints 3 extra.

    Great service to everyone. I have used your calculator for over 10 years.


  6. Hey Bret your amortization schedule is my favorite tool for what I do. I usually like to print out the schedule. tried this AM and all I get is Vertical lines where the numbers go . Can you help me on this one. The deck page prints fine …thanks

    1. Hi, David. Things look OK to me on the browsers that I use, but I will look into it. What browser and operating system are you using? Is it only the print function that’s not working properly? or does the schedule not display on the screen at all, either?

  7. I am trying to do a few amortizations for a 20-year annual payment, and when I hit the “Calculate” button, it changes my Principal amount so the result is very bizarre. When the principal amount is $361,400.00, for instance, the calculator suddenly turns it into $361. Is there something I can do to rectify this? I’ve tried to use other online calculators, but they seem to all be set up for monthly payments only. Thanks for any help you can provide!

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