DIY Excel-based financial independence calculator?

[drobots]

Hello! I'm hoping someone here has built an Excel spreadsheet they might share to help calculate financial independence, retirement, etc.  Here's my specific problem:

My wife and I are pouring money into tax-deferred accounts and have no debt except for a mortgage we'll pay off in about 7 years.  Our combined incomes make us ineligible for a Roth right now.  We have a financial planner friend who ran some fancy software and can predict our monthly income every year until we're 100+ and show how it changes as we tweak the scenario. But he's not Mustachian and can't plug in things like a 401k-->Traditional IRA-->Roth conversion ladder (http://www.madfientist.com/traditional-ira-vs-roth-ira/) and other tactics we'll need to bridge us between now (we're 33 and 40) and when we can actually access our tax-deferred retirement accounts (~60).  I'd like to work on a spreadsheet that I can update monthly and input income and expenses and watch how things change. I also want to estimate things like when we can quit our jobs, how much we can make during the Roth conversion thing and pay no taxes, when SS vs. 401k money will kick in, etc.

We use Personal Capital to track every account we have, and YNAB to budget so we consciously get better at cutting expenses every month.  So if I had a program or spreadsheet to plug updated numbers into every month, the numbers would be readily available.

Any thoughts?

[Thegoblinchief]

Not sure about Excel sheets, but cFireSim is pretty powerful for one-time simulations.

Personally I wouldn't bother with something as detailed as you're describing. Get a rough idea of a FIRE number, then only run simulations with your assets once you're 1-2 years away at the earliest.

[MDM]

...fancy software...can't plug in things like a 401k-->Traditional IRA-->Roth conversion ladder

Really not all that fancy then, is it?  Perhaps your friend could pass this comment back to the software vendor - maybe it could be added in a new version?

Agree with Thegoblinchief that www.cfiresim.com is likely the closest readily available tool for what you want.

Feel free to use whatever you want from the Reader Case Study spreadsheet if you want to roll your own and don't want to start with a blank sheet - it's decent for a snapshot view but doesn't come close to the time-dependent options you describe - cFIREsim may.