select
substr(t.tablespace_name,1,30) TABLESPACE_NAME,
round(sum(t.totalbyte)/1024/1024,1) "Total MB",
round((round(sum(t.totalbyte)/1024/1024,1)-round(sum(t.sumbyte)/1024/1024,1))/round(sum(t.totalbyte)/1024/1024,1)*100,2) "Used%",
round(sum(t.totalbyte)/1024/1024,1)-round(sum(t.sumbyte)/1024/1024,1) "Used MB",
round(sum(t.sumbyte)/1024/1024,1) "Free MB"
from (
(
select tablespace_name,sum(bytes) totalbyte,0 sumbyte
from dba_data_files
group by tablespace_name
) 
union
(
select tablespace_name,0 totalbyte,sum(bytes) sumbyte
from dba_free_space
group by tablespace_name
)
) t
group by t.tablespace_name
order by TABLESPACE_NAME;