I'm 35, and have been saving for retirement and maxing out my 401(k) ever since I started working. I don't think I'll ever have 4 million dollars in my retirement account, but I think (hope?) I'll be fine.<p>I think it's the numbers that are suspect in this analysis.<p>1. The calculator asks for your salary, then uses your current salary to determine your need for money in retirement. If you're saving 20% of your salary, then really you are only living on 80%, and that 80% should be used as your 'living expenses money'.<p>(fine print of calculator: We then assume you can live comfortably off of 85% of your pre-retirement income. So if you earn $100,000 the year you retire, we estimate you will need $85,000 during the first year of retirement.<p>I think it should be at least 85% of what you're not saving. For example, if you're making 100k, saving 20k, then really you should take 85% of 80k, which is 68 - not 85.<p>Also costs change as you get older. While you may spend more for health care, you hopefully won't have to pay rent, for raising children, etc.<p>Finally, they seem to say they want to take all the money and purchase an annuity. It seems like as soon as you retire, your money stops growing (other than for inflation) because of the annuity, but if you kept that money growing while you were retired, it would probably be even less.<p>Really the big trouble is you can't rely on ever increasing markets with some 7% yearly rate of return. It could be higher, it could be lower. If it's lower for a long time, basically the US retirement systems (both 401k and pension) are in huge trouble.