Personal Finance Decision, Tracking, and Projection Tools

Helping You Make Critical Decisions on the Way to FI, and Looking at Lots of Pretty and Exciting Plots

The tools below are built using a popular programming language called Python, which is both easy to learn and run. You can download the Python script file for each tool from the Engineering Your FI GitHub page

September 2022 update: I’ve now placed an embedded Python interpreter in many of the posts corresponding to these tools, which means you can edit the inputs and/or code and then run directly from the post! See the “Code” section in each post, which you can access easily via the Table of Contents at the top.

One day I may create nice graphical interfaces for these tools, but for now I’ve made it as easy as possible to modify and run these Python scripts. All user inputs are in a distinct “Inputs” section at the top, so all you have to do is tweak those to your liking and hit run.

If you’d like to install and run Python on your computer, you can download it and follow any number of great instructions available. I also recommend downloading and installing PyCharm (my favorite) or VS Code, which are programs that make it easier to edit and run your code.

If you’d rather not deal with installing Python and you’re not a fan of the Python interpreter I’ve placed in each post, you can also use one of the many other online interpreters (though I have not tested my scripts on these):, Tutorialspoint, Geekflare, Programiz,, OneCompiler, OnlineGDB, PYnative, CoCalc, Online Python.

Accounting for Investment Opportunity Costs

Choosing the Optimum Health Insurance Provider and Plan

Computing Your Time To Financial Independence for Your Savings Rate

Compute Your Time to Debt Freedom and Then Subsequent Financial Independence

Assess the Impact of Expenses or Income Growth Relative to Inflation on Time to FI

You’re FI / Retired! Or you’re about to be! Time to see how your collection of assets will fare with different withdrawal methods.

Compute How Much of Your Social Security Income Is Taxed

For a given Social Security Income (SSI), compute compute the maximum non-SSI standard income and long term capital gains you can have such that you pay no federal income taxes.

Potential Future Tools

Let me know if you’d like to see one or more of these tools sooner rather than later!

FI Projection Tool

Computing Your Exact Day of Freedom!

How Much Can I Invest?

Projecting Expected Expenses to Compute Exactly How Much You Can Invest Each Month

Credit Card Selection tool

Selecting Your Optimal Next Credit Card

Travel Rewards Credit Card Tracking Tool

Tracking Tasks for Credit Cards You’re Using to Travel for (mostly) Free

Expense Tracking Tool

Tracking All Your Expenses, both Monthly and Yearly

Money Saved By Biking

How Much Money You’ll Save By Biking Instead of Driving