Are you aware that, you have to include your 401K retirement amount (minus the fees and penalty) in your Zakat calculations?
I was not aware of this till this year and I am trying to figure out what amount will be received to me if I supposed, did cashed out all the amount today.
On this web site, it has detailed a very simple and easy calculator for the 401K, make sure to enter your federal tax rate as, it may not be the default 35%.
http://tools.nadart.org/calculators/LumpSumDistributionCalculator.cfm
~JazakAllah