Your annual statement from SS should include both individual and employer contributions.
For me, it was roughly $117k for each, from 1963 to 2009 when I ER'd at 60. I claimed at 63 with $24k per year. So full payback in less than 5 or 10 years, depending on how you look at it.
Since SS also includes disability, inflation and survivor benefits I see it as a damned good deal. Kudos to FDR!