TSQL - Simple Table Size Query

Simple query for table size information.

SELECT t.Name,
    SUM(a.total_pages) * 8 AS TotalSpaceKB,
    SUM(a.used_pages) * 8 AS UsedSpaceKB,
    (SUM(a.total_pages) - SUM(a.used_pages)) * 8 AS UnusedSpaceKB
FROM
    sys.tables t
INNER JOIN
    sys.partitions p ON t.object_id = p.OBJECT_ID
INNER JOIN
    sys.allocation_units a ON p.partition_id = a.container_id
GROUP BY t.Name
HAVING SUM(a.used_pages) > 0
ORDER BY TotalSpaceKB Desc