filing 1040- QSS form 1116.My F Div. $ 822 , FTP $ 550.TT calculate $ 160 CR and $390 carry to 2025. Why can't I get full credit 0f $550 in 2024 ?

Your foreign tax credit is limited to the lower of the foreign tax paid OR the US tax on the same amount.  Your tax rate is 20% and the tax on $822 is $160.  That's the maximum deduction allowed.

@JRPATEL-AHMEDABAD