I've gone and made a spreadsheet projecting my retirement fund from now until 2049, which is when I'm 65.
Voila! (Link must be opened in Firefox 1.5+ or Internet Explorer 6.)
I'm assuming an average annual rate of return of 8%.
I plan on maxing out my Roth IRA every year until I retire, including my grad school years, if they come to be. I know max contributions will rise, but I just kept it at $4000/year since I don't know when it'll rise, or what it'll rise to.
I also plan on contributing $10K/year to my 403(b) for the next two years, and $15K/year for the following two years, and then stopping (for grad school?). I don't pick it back up at all in this set of projections, although I probably will in reality.
At the end of 2049, I will have earned $1.88 million tax-free dollars from my Roth from an input of $184,377.96.
I will have over $900.000 in my 403(b) from a total input of less than $35K.
The net worth of my retirement fund at 2049 will be $2.79 million.
Someone please pinch me? 
Retirement projection spreadsheet
September 11th, 2006 at 04:13 am
September 11th, 2006 at 04:26 am 1157948769
You don't really want that pinch, do you? But if you're a glutton, use those time value of money equations and make your assumption about inflation (3-4% is typical). You'll still have a tidy nest egg, and you'll still have your 2.79 million dollars, but it will feel like substantially less once you account for inflation.
September 11th, 2006 at 04:38 am 1157949518
Self Pinch. "Past performance does not predict future results." Who knows if you'll get 8%, who knows what's going to happen in your life, who knows what's going to happen to the US economy...
September 11th, 2006 at 05:34 am 1157952865
Here is the calculation of what $2.79 million would be worth now, assuming an annual inflation rate of 3.5%:
PV = FV * (1 + i) ^ (-n)
= $2791750.52 (1 + 0.035) ^ (-44)
= $614,470.751
Okay, now that's kind of depressing. But I'm underestimating just about everything--the rate of return, the compounding frequency (I'm using monthly compounding when it's probably closer to daily), and even the contributions.
I'll add an extra column that adjusts for inflation for the net output. I wonder what it'll take to actually grow an inflation-adjusted $2 million.
baselle: Yes, people keep pointing out that I might die before I get to cash in on retirement, therefore investing is a bad idea. I kind of prefer to assume that I'll live, however. To a ripe old age, even. Call me an optimist!
You can't predict the future. You can only plan to the best of your current knowledge and abilities, right?
~mimi
September 11th, 2006 at 01:54 pm 1157982893
While an inflation-adjusted 2 million would be nice, you don't really need it. If you have 2.79 million and by that time have moved it over largely to conservative investments--say ones that bring in 5%/year--the interest on those is $139,500--the equivalent of $31,789/year today, WITHOUT even touching your principal. So you should be able to live a modest life style without even touching the principal, and a nice one if you draw down a bit (the conservative estimate for drawing down your retirement funds to make them last your entire lifetime is a withdrawal rate of 4%/year, or 111,600, the equivalent of another 25,423 today. So you should expect to have the equivalent of 57,212/year in today's dollars to live off of then--not rich but certainly enough to enjoy life!