Assuming that $7,000 of net profit from self-employment represents your only compensation for the year, your maximum permissible contribution to the Roth IRA (or to a traditional IRA) will be less than $7,000 because a portion of the $7,000 goes to the deductible portion of self-employment taxes. The sum of the deductible portion of self employment taxes and the amount of your Roth IRA contribution is not permitted to exceed the net profit.
With exactly $7,000 of net profit and no other compensation, the deductible portion of self-employment taxes would be $495 and your maximum Roth IRA contribution would be $6,505.
