About & methodology

Penny Runs the Numbers is a small, independent project. Penny, our piggy-bank host, runs one money question per page and per video, and shows every step on a calculator you can use yourself.

How the numbers are made

Each calculator is a small, tested model. Inputs come from primary sources (for example Freddie Mac, the National Association of Realtors, the Social Security Administration) and are dated on each page. Where no market number exists, the page says it is an assumption and lets you change it.

What we don't do

We don't sell financial products or give personal advice, and nothing on this site is a recommendation. We don't run third-party ads or trackers.