An Estimate for Needed Retirement Savings

Source: http://www.aon.com/attachments/human-capital-consulting/The_...

10 pages of analysis for the conclusion that if you want to maintain your lifestyle for 23 years after you retire, you'll need 23 * 0.65 (no income tax on savings) * 0.75 (social security income) = 11 years income of savings.

So if you want to live for a year without working, you'll need to save a year's worth of income.

The analysis doesn't say whether that is pretax or post-tax (I'm guessing pre-tax), with is a huge distinction.