Let me walk you through my thought process... So I'm currently 25 yrs old, and have been in the workforce for 2 years now. Now that I've got my feet pretty well settled down and planted, I'm starting to really hammer away at saving for retirement. I've currently got $12k saved away mostly in my Simple IRA, but I've also got a Roth IRA and a taxable account set up ($100/mo each).
I'm expecting to increase my FI/RE contributions by around $500/mo starting next month, but I can't decide on where I want to put them. My original plan is to put all that in my Simple IRA and then keep the $100/mo going for my Roth and taxable, eventually maxing out my Simple ($1000/mo) and then work on maxing out Roth. But where I'm getting hung up on is what if when I reach FI, I actually do want to pull the trigger and RE. If the vast majority of my money is in Simple/Roth IRAs, then I can't really access it until I'm 59.5. What do I do until I reach that age? My only answer is to start contributing to my taxable and live off that account until I can withdraw from my tax-deferred accounts.
So since I (like many of us here) love spreadsheets, I've created one that roughly calculates my "Net Worth FIRE Goal," basically last year's expenses times 25. I'm not treating it as a defacto number, but a loose goal. I then calculate how many years it will take to get there based on last year's savings and liquid NW using F/P and F/A formulas (
http://goo.gl/WnWlLm).
I also calculate what "FIRE Income" I'll have using a SWR of 4% based on last year's liquid NW; however, this assume that I have open access to all of my accounts. Should I be breaking it up between my taxable and tax-deferred accounts to calculate that? Also, from a conceptual standpoint, what would be a good way to construct the spreadsheet, so that way I'll know how much I can pull from for taxable and tax-deferred accounts?
I have a decent idea of how to do this, I just need some validation and maybe some other ideas that will help clear it all up. I'll be updating the spreadsheet annually during tax season.