SELECT TABLESPACE_NAME, FILE_NAME, BYTES/1024 AS MBytes , 100-trunc(result/bytes*100,2) as free_per , (BYTES - RESULT) / 1024 AS FREE_MBTES , RESULT/1024 AS USE_MBytes FROM (SELECT E.TABLESPACE_NAME,E.FILE_NAME,E.BYTES, (E.BYTES-SUM(F.BYTES)) RESULT FROM DBA_DATA_FILES E, DBA_FREE_SPACE F WHERE E.FILE_ID = F.FILE_ID GROUP BY E.TABLESPACE_NAME, E.FILE_NAME, E.BYTES ) A ;