Building a Financial Calculator, What would like to see?


Am building a set of financial calculators. What types of calculators would want to see.

Some ideas
How much house can you afford?
Student debt repayment plan?
Credit card payment plan?
How much do I need to retire?
Expected return vs risk on the investment?
What would it take to quit my job?

Fill me in with any ideas you have. Thanks


Hey pOSL, I’m curious what technology you will use to build the calculators. Will you have downloadable Excel sheets, embedded Java, etc…? Thanks!


Hey BeNetWorthy, this is going to be a web application using JavaScript. Hopefully I can make it up to par with what you would get from excel.

Do you have any Ideas or what would you like to see or know of any community or folks who would be interested and like to comment.


You may want to do some “what if” calculations on paying down your student loans earlier, e.g. how much extra to pay per month to have the loans paid off by a certain time, or how much lump sum to have them paid off at a certain time. Also, you could calculate the total interest cost for borrowing the money. Just a few ideas…


Wow love that idea. Didn’t think of that. Will definitely add that to the list. Are you by any chance an excel genius or finance guru. Maybe I can learn some formulas from you.



Great, glad you found it helpful! Unfortunately, I’m probably not the best guy to help you with the formulas.


FIRE Opportunity Cost Calculators: spending now in terms of retirement funding.


Hey PappG, could you elaborate more on this. Am not clear on this Calculator.



Calculate the cost of x (buying or spending for something) in terms of retirement funds and time period. See For example, if you’re 18 and want to buy a new gadget for $399, the calculator what it will cost in FIRE dollars (i.e. Retirement dollars) for buying that gadget.


Correction. “… the calculator will tell you what is will cost in FIRE dollars …”


Gotcha. i will rad up on the link you sent me. I like the idea of an opportunity cost calculator.