I'm running some scenarios for 2021 and could use some assistance. I have never had a sole proprietor with a solo 401k. I am inputting a Schedule C net income of $60,000, also has wages of $100,000 from another employer (no retirement plan). Assume taxpayer is over age 50, MFJ, and makes maximum 401(k) contribution allowed. I calculate he would get a schedule 1 deduction for $37,425 for the 401(k), correct? When calculating QBI, I don't understand the income amount the program calculates, which is QBI of $27,885. It begins with the $60,000, deducts 1/2 of s/e tax of $2,877 and $29,238 for the s/e pension. Anyone know how the $29,238 is calculated? I'm totally missing something or have something coded incorrectly. Thanks!