Kaffara of qadha namaaz after death

Bismillahi Ta’ala

Walaikum Assalam Warahmatullah

Penalty for unperformed salah is calculated for those prayers which were not performed in their time and died, or one was unable to perform them due to some terminal illness.

The value for this is same as fidya of one missed fast. We have a general answer on that here: https://qna.ilmhub.com/question/guidelines-about-fidya-for-missed-fasts-or-prayers/

I am also attaching the current indicies for Nisaab and Fidya (Dec 2023).

Wallahu A’lam

And Allah Ta’āla Knows Best
Mufti Faisal al-Mahmudi