Social Security and friends in the US are approximately 7.5% deduction from an employees "advertised" income, plus about the same on top of (called the "employer's portion") that is not advertised as part of the salary. It is a bizarre format.
Social Security is 6.2% employer, 6.2% employee...but most economists would say that the employee pays both halves, since the cost is directly related to a specific person's job. (this year there's a temporary cut in the employee half as a stimulus measure)
There's also a similar 50/50 Medicare payroll tax that totals 2.9% of each worker's salary.
Total hit on most Americans for both programs is 15.3% of gross income.
What's scary is that is nowhere near enough revenue to sustain either.
I apologize for commenting on a downvote, but what I wrote was a simple and accurate answer to parent's question, with only a mild bit of opinion at the end.
