With $30,000 of net profit from self employment (and no W-2 compensation that would cause your SE tax to be limited and your SE tax to be less), SE tax would be $4,238. Half of that, $2,119, would be the deducible portion of SE tax, leaving $27,881 as net earnings. The maximum SEP contribution would then be 20% of $27,881 which is $5,576, leaving $22,305 of compensation to support the $8,000 Roth IRA contribution.
