With eligible compensation only from self employment, the amount that you can contribute to an IRA is your net profit from self-employment (Schedule C line 31) minus the deductible portion of your self-employment taxes. With exactly $3,000 of net profit, your maximum permissible Roth IRA contribution would be $2,788.
Keep in mind, though that if your modified AGI exceeds certain limits, the amount that you may contribute to a Roth IRA may be limited. See,
How Much Can Be Contributed?:
https://www.irs.gov/publications/p590a/ch02.html#en_US_2015_publink1000230988
