"What is the adjusted rate for tax on Schedule C?"

Bob, I can't decide if you really don't know this, or just want me to prove that I know it. I will show it to @joe7230 just because Bob still wrote it incorrectly.

It's on the Sched SE, as I noted. Not Sched C; there is no tax like this on the Sched C. That's similar to how the health insurance deduction for employees would be on the Sched C but not for the sole proprietor. The Sole Proprietor has these items on their Form 1040.

If you are filing Sched C and you have employees, their employer share of employment taxes (social security, medicare, unemployment) is on Sched C. The Schedule SE has the computation, the adjustment, and the deduction (which goes to the Form 1040) for the nonwage owner.

I often address this to people who complain about being 1099-NEC "and now I have to pay both parts of the taxes." The "employer" entity gets a consideration for it, as parity to employer's match to employee share. It's the 92.35% you see on the Sched SE. You follow the math to the point that you compute the Social Security and Medicare on a reduced amount of business income than is on the Sched C. Then, the 50% deduction goes to Schedule 1, part of Form 1040 and not part of Schedule C (business).

You can't use the amounts a sole proprietor "paid" themselves for taxes owed, because that isn't taxable directly (draws are not an expense and are not a taxable event). It's money taken from the business taxable income, which requires an SE tax and also deserves a credit, and that credit makes a reduction in business income (but not as a Sched C line item deduction), which reduces the tax, which reduces the amount on which the adjustment is based, which reduces the credit.

If you were to do this manually, you see the formula is recursive. That's why it is adjusted. 

For employees, you get the tax deduction in full as a business deduction.