Script to find Table size in a database

Script to find Table size in a database.

select sum(BYTES/1024/1024) as TOTAL_GIG from user_segments where
SEGMENT_NAME = 'TABLE_NAME';

Note: Need to execute as owner of the table.

(OR)

select sum(BYTES/1024/1024) as TOTAL_GIG from dba_segments where SEGMENT_NAME='FND_TS_MIG_CMDS'