Example -- summer job as a baseball coach generated a 1099-NEC for $1,049 of self employment income. TT calculates $74 in self-employment tax, and further calculates Roth IRA contribution limit of $1049-74 = $975.
The IRS earned income publication does not make any mention of subtracting self-employment tax:
Earned income includes all the taxable income and wages from working either as an employee or from running or owning a business. It also includes certain other types of taxable income. Earned income includes:
Wages, salaries, tips and other taxable employee pay
Net earnings from self-employment
Union strike benefits
Long-term disability benefits received prior to minimum retirement age
