let's see, SS is what a 15% deduction? so, it takes 6.67 years for them to put in 1 year's worth of salary, though for most people it would take them twice as long since the employer is paying for 1/2 of it. 65 - 18 = 47. 47 / 6.67 = 7. so basically, everyone who has paid into social security has only contributed 7 years of worth of the salary that they made by the time they retire. how you translate that into they contributed enough to live 20-30 years off of it?