After you have contributed a maximum to your 401k every year, contribute at least 20% of your after tax income after 401k contribution to your savings or retirement portfolio accounts. That way, you will have potentially DOUBLE the amount in total retirement saving if your household income is $100,000 or more.he average 401k balance as of May 2015 is around $92,800 according to Fidelity’s 12 million accounts, thanks to an incredible 30% rise in the S&P 500 in 2013, followed by another 13% increase in the S&P 500 in 2014.