It is not 30% , it is 15.3% over 92.35% of your net self employment income.
For example : 10,000 x 92.35% = 9,235
9,235 x 15.3% = 1,413 : this is your self employment tax
This SE is your SS and Medicare taxes, you have to use form schedule C-EZ and SE to report .
There're 3 different taxes for you:
1. Self-employment, also known as Social Security + Medicare. This one is a little less than 15% of your entire 1099 (but possibly reduced with business deductions such as supplies and driving). So possibly $1,500.
2. Federal income tax. Impossible to tell you how much. It depends on your family status and other income. Could be as little as zero if you had no other income.
3. Michigan state tax. Again, depending on your other income and family status - could be about $300 or even less if no other income.
As you can see, the biggest hit is SE tax, and it's under 15%. Basically, half of what you feared. Of course, if you had other income, your SE tax will not increase, but both Federal and Michigan income tax could.
Michael Plaks, EA, Houston TX