from a previous answer:
For self-employed people, that rate is actually 20%. In researching this, I found a helpful IRS link that you should be very interested in. Pay particular attention to a worksheet entitled Deduction Worksheet for Self-Employed. Here it instructs you to enter your deduction for your self employment tax. Your deduction that is listed as an adjustment to income is listed in Schedule ! of your return and is 1/2 of your actual Self-employment tax imposed on your net earnings.
