Oracle : Archived log block size

Let us keep in mind that block size of archived log files are not same as database block size i.e. db_block_size. 

If we calculate the size of archived log as "v$archived_log.blocks * < value of db_block_size parameter>" that might not be correct. 

The block_size column of v$archived_log view shows the logical block size of archived log. 

We should calculate size of the archived log as below, if we are not checking the size of file using OS commands. 

select thread#,sequence#,name,blocks*block_size/1024 size_kb
from v$archived_log
order by sequence#
/

There are situations where we have to calculate archived log size using programs.The above query might be helpful on those situations.