[tx_eggman]

Now 7.65% on the first $90,000

Currently it's 10.4% of the first $110,100

4.2% from the employee / 6.2% from the employer

or

10.4% if you're self employed

[Ratman83]

Under the Federal Insurance Contributions Act (FICA) 12.4% of earned income up to an annual limit must be paid into Social Security, and an additional 2.9% must be paid into Medicare.

If you’re a wage or salaried employee, you pay only half the FICA bill (In 2012, 4.2% for Social Security plus 1.45% for Medicare), and the tax is automatically withheld.

Your employer contributes the rest.

If you’re self-employed, however, you’re expected to cough up both the employee and the employer share of FICA. You are, however, permitted to deduct half of this self-employment tax as a business expense.