You appear to have sufficient compensation to be able to make a nondeductible contribution to a traditional IRA. There is no limit on how much you are permitted to convert to Roth and if you have no other money in traditional IRAs, your conversion will be tax free.
The calculation of the maximum employer contribution is done on the Deduction Worksheet for Self-Employed in IRS Pub 560. TurboTax implements that worksheet as the Keogh, SEP and SIMPLE Contribution Worksheet.
