select total.tablespace_name, round(total.MB, 2) as Total_MB, round(total.MB - free.MB, 2) as Used_MB, round((1 - free.MB / total.MB) * 100, 2) as Used_Pct from (select tablespace_name, sum(bytes) / 1024 / 1024 as MB from dba_free_space group by tablespace_name) free, (select tablespace_name, sum(bytes) / 1024 / 1024 as MB from dba_data_files group by tablespace_name) total where free.tablespace_name = total.tablespace_name;