How much taxes do i have to pay if im self employed?

In 2009, you will pay the regular state and federal tax rates on all of your income, including your self-employment income.

In addition, you will pay a Social Security tax of 12.4% on the first $106,800 of your net self-employment earnings (reduced by other earnings subject to SS) and a Medicare tax of 2.9% of your net self-employment earnings with no limit.

You should also investigate whether you need to make quarterly estimated tax payments to avoid possible penalties for underpayment.