Amortization Calculator – Bret's Blog (2024)

This update is long overdue.

The world of web pages has grown smaller over the years. That is, web pages are increasingly geared toward hand-held devices like phones and tablets. The design I had for so long was still targeted at desktop screens.

I published a new responsive design of the amortization calculator pages which now scale better for smaller screen sizes. For now, the color scheme is mostly the same, and the calculations themselves should not be affected. I hope you’ll not notice any serious change in behavior.

But it’s always possible that I messed something up along the way, so if something breaks for you, or if some formatting seems particularly wonky, please let me know!

Over the years, a lot of people have asked for calculator features like occasional extra principal reduction payments, tracking fees or late charges, summary of interest over a fiscal year. My pat response is “this kind of thing needs a spreadsheet or special-purpose software.”

Well, I’ve taken a little time to work up a basic amortization spreadsheet. It doesn’t have all the calculation options that the web calculator provides (it only calculates the payment, for example), but the amortization schedule it produces will allow one to track extra payments and fees, to include payments for insurance and taxes, and it provides a nice fiscal year summary of interest paid.

It took a few days of playing around with Excel to get it working mostly right, and it’s free for you to download and try, if you’re into that kind of thing. Maybe it will give you some ideas about how to build your own custom spreadsheet. But of course, use at your own risk! Please don’t base any high-finance decisions on the spreadsheet’s results until you’ve verified that it’s doing everything correctly. Like the web calculator, I consider this a planning tool only!

If you want to give it a shot, here’s a link to the spreadsheet. Enjoy!

I just can’t help myself: when I start to tweak things, I start coming up with more ideas for making things a little better or easier. Nothing dramatic, just little things.

Today’s idea was to make it easy to identify that point in the amortization schedule when the principal component of a payment first exceeds the interest component of a payment. Let’s call that the cross-over point. If you run an amortization schedule now, the cross-over point is highlighted in green. There may be schedules without a cross-over point (usually shorter term loans), in which case there’s no special highlighting.

Who knows what might come next, now that I’ve started tweaking. 🙂

I’ve made some slight modifications to the schedule display: alternating rows of the table now have color bands to help identify rows more easily. In the process, I was also able to reduce (slightly) the amount of HTML that’s generated, allowing the schedule to download and render more quickly (though this is hardly an issue for most of us these days).

For people generating hard copies, I made some very minor tweaks as well. I don’t know if it makes things any better or not.

Through trial and error I have played with the calculator’s web appearance. I think it looks more attractive, and I hope you do too. I would never claim to be a graphic designer, but I do what I can.

Credits:

• Background graphic: squidfingers.com
• Design ideas: CSS Zen Garden
• Color scheme: inspired by Uncultivated by Mario Carboni
• Image editor: The Gimp

Hi, folks. I’ve heard from a few of you who have said that you have difficulty printing schedules, or that schedules produce a lot of blank pages. I still haven’t experienced this problem myself because I can’t test every browser/printer combination available.

However, I have tried to make some changes to the HTML that the calculator produces. For those of you who had printing problems, please give the calculator a try now, and let me know if things have improved any (or if they’ve gotten worse, or if nothing has changed).

Thanks!