Tablespace Usage Info (Free Space, Used Space, Percentage)

Solution:

select round((bytes/1024)/1024,0) "Used Space(MB)",
round(total,0) "Allocated size(MB)",
round(max,0) "Maximum allowable(MB)",
round(max-(BYTES/1024)/1024,0) "Effective free(MB)",
round(((max-(BYTES/1024)/1024)/max)*100,2) "FREE(%)"
from SYS.SM$TS_USED,
(select sum((BYTES/1024)/1024) total, sum((decode(MAXBYTES,0,bytes,maxbytes)/1024)/1024) max
from dba_data_files where tablespace_name='&1') where tablespace_name='&1';
Note: Pass Tablespace whenever you are prompted