Assuming that you are a sole proprietor do not have another job which would cause to to max out the Social Security wage base, with $10,000 of net profit you have only $9,293 of net earnings. Net earnings are net profit minus the deductible portion of self-employment taxes.
With $9,293 of net earnings you can contribute $9,293 as a Roth contribution to a 401(k) and $6,500 to the Roth IRA. Only deductible 401(k) contributions reduce the amount of compensation available to contribute to a Roth IRA, so the same dollars used to support the Roth 401(k) contribution can be used to support the Roth IRA contribution.
