I just did a simple spreadsheet where I used the numbers off of the final paystub of 2012 to do a quick estimate of what my current spending actually is so that I could see how that relates to my possible retirement budget
I took the yearly Gross pay number and subtracted out;
Federal income tax withholding
State Income tax withholding (I don’t expect a large refund or payment on either)
Group life insurance I am paying
This gives me my annual money that was available to me this year.
(There were other expenses on the paystub like my part of the health insurance, flexible account spending, etc that I will still have in retirement so I left these in. I currently pay for part of my employer provided health insurance so I assumed that what I am paying now will be similar to what a Medicare supplement will cost. )
Outside of my 401K I did not have any large net amount of savings that I added to or withdrew this year so I did not have to adjust for that.
My mortgage will be paid off by the time I retire so I also subtracted out what I paid on my mortgage this year.
I then looked up my social security estimates and subtracted that from the total.
I also have a small pension so I subtracted that out too
This left me with an estimate of what spendable income I would need to come up with in retirement to live like I currently do.
With taxes my needed income to have that amount of money after paying taxes would be higher.
This also does not budget for occasional large expenses like cars, roofs, etc or significant change in lifestyle
This is admittedly a quick and dirty estimate but for something that only takes five minutes to do it seemed to me to be good reality check on how close I am to having enough to be able to retire and what my income goal needs to be.