This should be a pretty easy calculation. Think of a realistic amount you need to sustain your desired retirement lifestyle. For argument sake, let's use $10,000 per month, after tax or $14,000 before tax. Multiply it by 12 months = $168,000. This is what you need to receive annually for the rest of your life. Then, make some reasonable assumption about interest rate you can safely count on from a good income-producing security of some kind (REIT, bond, income properties etc.). Again, for this example, let's use 5% return. Capitalize your desired pre-tax income: $168,000/0.05 = $3,360,000. This is what you need to have invested as a nest egg to assure $14,000 income for the rest of your life assuming that your investment safely delivers 5% return. The moment you have that amount (or equivalent) in the bank – call it quits and go fishing.
