Six percent annually.

That said, it is a fantasy, unless you intend on your retirement getting cut short by death prior to you exhausting your money. The standard recommendation for someone who is much older (i.e. can rely on death to moot insolvency with greater probability) is that the safe withdraw rate is 4%.

With a withdraw rate of 4% and a standard mix of stocks and bonds you can be fairly confident that, assuming the future looks something like the past, you will not run out of money within your lifetime. (Most people will in fact see their money "go infinite", i.e. their portfolio expands faster than their withdraw rate and when they eventually pass away their heirs and government get to toast their name quite a bit. However, the prudent investor doesn't plan on being "most people", they plan on being the unlucky sod who bought at the top and sold at the bottom.)