CNN Money answers this and offers retirement suggestions in a recent article:
It’s impossible to give a yes or no answer to your question because the length of time your nest egg will last depends on several factors, including how much you withdraw each year, how you invest and how sure you are that you can count on those withdrawals in the future.
One tool is Vanguard’s Retirement Nest Egg calculator. Even though this tool uses a sophisticated forecasting technique know as Monte Carlo simulation, it’s simple to use and interpret.
Begin by dragging the first of the tool’s three sliders to specify how long you want your portfolio to last. Given today’s long lifespans, you want to be careful not to enter too short a period. Your assumption of age 95, or 28 more years, seems sound.
Next, move the second slider to indicate the current size of your retirement portfolio — $600,000 in your case. Then drag the third slider to show how much inflation-adjusted annual income you’d like. You didn’t mention a figure, but let’s assume $30,000 a year, adjusted for inflation.