SET NOCOUNT ON

CREATE TABLE #results(Name sysname,Rows char(11),reserved varchar(18),Data varchar(18),index_size varchar(18),Unused varchar(18))

DECLARE @obj_id int
SET @obj_id = -2147483648

DECLARE @obj_name sysname

SELECT TOP 1 @obj_id = id, @obj_name = name FROM sysobjects WHERE ( xtype = 'U') AND id > @obj_id

WHILE (@@ROWCOUNT = 1)
BEGIN
  INSERT INTO #results
  EXEC sp_spaceused @obj_name

  SELECT TOP 1 @obj_id = id, @obj_name = name FROM sysobjects WHERE ( xtype = 'U') AND id > @obj_id
END

-- Prune off the "KB"
UPDATE
  #results
SET
  reserved = LEFT(reserved,LEN(reserved)-3)
  ,data = LEFT(data,LEN(data)-3)
  ,index_size = LEFT(index_size,LEN(index_size)-3)
  ,Unused = LEFT(Unused,LEN(Unused)-3)

-- Convert to
ALTER TABLE #results ALTER COLUMN reserved bigint
ALTER TABLE #results ALTER COLUMN Data bigint
ALTER TABLE #results ALTER COLUMN index_size bigint
ALTER TABLE #results ALTER COLUMN Unused bigint

SELECT
  Name
  ,reserved AS [Size On Disk (KB)]
  ,data AS [Data Size (KB)]
  ,index_size AS [Index Size (KB)]
  ,Unused AS [Unused (KB)]
  ,Rows FROM #results
ORDER BY
  reserved DESC

DROP TABLE #results