The Commerce Department reports a surprisingly low American savings average of under 2% and for those who are dutifully socking away 10% of their pretax income it may not be enough.
Jonathan Clements:

Just when folks ought to be saving more, they are saving less. Trouble ahead? You’d better believe it.
Yes, I have heard all the arguments about how the true savings rate is higher than the 1.3% calculated for 2004 by the Commerce Department’s Bureau of Economic Analysis, or BEA. But don’t let that distract you from the bigger issue.
In a world of disappearing company pensions, skimpy bond yields, rich stock valuations and rising life expectancies, anybody interested in a comfortable retirement should be saving a truckload of money every year — and yet most folks aren’t.
Rate debate. Among pundits, belittling the official savings rate has become something of a national pastime. Some of the arguments seem a little suspect, like the suggestion that buying televisions, cars and other consumer durables ought to be considered saving rather than spending.

and stock-market gains don’t count:

Other criticisms are more valid. For instance, stock-market gains don’t count toward the official savings rate, which strikes me as the right way to do it. Problem is, under the BEA’s methodology, if a winning stock is sold and capital-gains taxes are paid, that tax payment reduces the savings rate.
Still, the impact isn’t huge. Even in a big year for capital-gains taxes, like 2000, removing the tax impact would boost the savings rate by a mere 1.7 percentage points, calculates BEA research economist Marshall Reinsdorf.