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Pay Down Calc v2.0 - A Resource For Consumers and Agents

Jan 2018

After 6 months of effort, I am pleased to announce Pay Down Calc.

Pay Down Calc Logo

This is the 3rd rewrite of my popular calculator that I originally launched back in 2012. The first one was crushed when it was front-paged by Reddit. Though the second version survived Reddit, development stagnated. This version is a complete overhaul that now features retirement forecasting.

Motivation 2012

Way back in 2012, my wife was researching ways we could pay off our house. Surely, there is a good online calculator to help? After a couple days of browsing the internet, my wife came to the conclusion: Every mortgage calculator was terrible. If they aren't awkward to use, they at best only offered "extra monthly".

She asked me if I could write a better one. She told me what she wanted that did not exist: Fast, Free, Privacy-driven, and lots of knobs to adjust extra payments.

It was a 3-month process, but Pay Down Calc emerged. It quickly became a hit: Who wouldn't like a very nice calculator with absolutely no ads, tracking, or data-mining? I posted it to Reddit, it got gilded, and then died the same day. The takeaway: "Pretty cool, but it is kinda slow."

So I failed on the "fast" requirement. After a couple more weekends, I fixed the slowness (feel free to ask me how), and Reddit traffic is now happy.

I have no idea how many mortgages I have calculated over the past 6 years. Like I said, the app is privacy-driven. I track nothing. This is intentional.

Motivation 2017

Fast forward to 6 months ago 😁.My wife and I are no longer concerned about mortgages. My wife has another request: Can Pay Down Calc calculate retirement? Her complaint about other retirement calculators is the same: they are all terrible. At best, you get a simple compound interest calculation demonstrating the importance of investing early and investing often (and then a "Contact Us!" link).

With little to go on, I recreated the standard compound interest calculation and then added my own idea called "life events" (such as buying a car, going to college, etc). I then gathered some feedback and made some cosmetic adjustments.

I did not call it done yet. For this rework, I wanted some kind of monetization strategy. Maintaining apps powered only by "thank-yous" gets exhausting after a few years. Surely, there is a way to build an app that respects privacy, helps users, and can still remain free? Is that possible? Maybe not, but I wanted to try.

I divided my audience into 3 segments. I wanted this tool to serve Consumers, Agents, and Advertisers. Other Designers and Developers may know this strategy as "User Stories".

The Consumer just wants to calculate and then leave. They do not want to be tracked, data-mined, be charged for anything, forced to create an account, etc. I can handle this fine. This is the version that ran previously for years. My goal here was that the app should load very fast, do the calculations, and then they can go on their way. I could never earn much from consumers, so I am not going to try. However, there is one change I can do: Consumer could help share my app. Therefore, I added easy share buttons (which still respects privacy).

The Agents are Pay Down Calc power users. The previous version had a handful of loyal agents calculating mortgages to send to clients. They were playing "what if" scenarios with mortgages to help sell houses. I decided agents are my best chance for potential revenue. My thought process: What would an agent want in this web site? My answer: They would want this web site to be THEIR web site. Thus, landing-page personalization was born. I gave it the absurdly cheap price of $9/year. My reasoning behind that: For the past 6 years, I was not charging anything. I want this to be an impulse-level purchase.

I didn't want to leave it there. Surely, beyond helping share the site, there is some value in the traffic from Consumers? I decided to open the site to Advertisers. However, I still need to respect privacy. To do this, I made all the advertising native. Did anybody actually see your ad? I served it. Did anybody see it? Who saw it? I simply do not know. These are questions Advertisers want to know, but I cannot answer. That's why my advertising is very cheap too. It is discounted for lack of data. Also, same reason as last time: For the past 6 years, I was not charging anything.

It was a very long 6-month development timeline. I had to build social logins (that still respected privacy). I had to build a subscription payment system. I had to build self-serve advertising (that also respected privacy). On top of all that, the old app still needed to stay running and free for Consumers.

I hope I hit all the right checkmarks. I hope all three market segments finds the app useful. So, to each...

Dear Consumers

Your needs are first and foremost in the design. I invite you to play with the loan and retirement calculators.

  • This tool is completely free.
  • Even creating share links is free.
  • This tool is very privacy-focused.

Pay Down Calc is not tracking you. Your data is safe -because it is not being stored.

Dear Agents

I'm certain you will agree with the statement: Anything that will help lead conversion is welcomed.

I want this tool to help you. That is why I put together an extremely low-cost and easy way to whitelabel my calculators. When you create share links to send to your clients, you may wish to put your picture, logo, and contact information alongside the calculation. When your client then lands on your page, YOU will be front-and-center.

If the client shares your link, your information will be shared too. This is the cheapest lead-generation price you'll ever see: $9/year.

Dear Advertisers

The top-right corner is a simple native text-based ad slot. Turn on your ad blocker and visit the site. Notice that your browser still shows the ad? That was intentional. This ad is very difficult to block. You will be seen (though the consumer is not tracked).

Native advertising is self-served and still respects the privacy of visitors. It is also very affordable.

Dear Everybody

I hope you find the calculators useful! Message me on Twitter if you have any comments.


Dan Nagle is a SW Developer and the founder of NagleCode. His apps have been downloaded hundreds of thousands of times. Contact Dan to speak at your event.

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