@wzy - Line 30 is based on your 2020 income, filing status and number of dependents under the age of 17
LESS
what you received on the 1st two stimulus payments
the result can not be less than zero.
if you want to provide more details, I am happy to explain the math .....or you can use the official IRS worksheet that TT is using - see page 59
https://www.irs.gov/pub/irs-pdf/i1040gi.pdf
