How much can I withdraw?

This is a little hypothetical, but not totally. OK, lets say i have
worked and saved, maybe inherited a little. Kids are grown and I am
60. I want to "retire". I have a nest egg, house is still mortgaged,
but I could pay it off. I do my budget and figure I need about $60K a
year, right now, and that much buying power in the future. I have $500
a month from Social Security, $2000 a month from a retirement (fixed
till I die). How much nest egg do I need?
Alternatively, and probably easier to answer, lets say I have $1
Million. How much can I take each year, and not run out. 4%, 5%, 8%?