A simple rule for the amount of income you can withdraw from a well diversified portfolio in normal economic situations is about $4,000 of income per year for every $100,000 invested.  Of course your unique circumstances and investment choices will cause this number to vary.  Using the above rule, following are yearly income amounts and the amount of retirement savings you will need to be able to achieve this income from investments. 

Yearly Income Desired                                        Retirement Savings Balance Needed

$50,000                                                                 $1,250,000

$75,000                                                                 $1,875,000

$100,000                                                               $2,500,000

$150,000                                                               $3,750,000