"Save $250 a month until you're 65, for example, and you would need a 10% annualized return to hit that $1 million target. I still consider that overly optimistic even for an all-stock portfolio, given the prices stocks are selling at today and the uncertainly surrounding the growth prospects here and abroad. Boost your monthly savings to $400, and the return you need falls to about 8% annually. Possible? I suppose. But perhaps still ambitious. ... ... Remember, though, having a million bucks 37 years from now isn't like having that sum today. In fact, assuming a modest 2.5% inflation rate, $1 million in 2047 would be the equivalent of having about $400,000 now. Or, viewed another way, you would need about $2.5 million in 2047 to have the purchasing power of $1 million today."