Between 3 to 6 million is probably the right answer. Anything in that range nets you at least a cool 40K on interest in a saving account after taxes and so you can be living alright for the rest of your life. Ideally if you keep expenses low, the money you make off the interest should be able to finance you property and investments. Not touching my money for 5 years before doing anything with it for sure, just travelling to low cost countries and exploring the world.