Space Used by All Tables

Set statistics time on
declare @PageSize float
select @PageSize=v.low/1024.0 from master.dbo.spt_values v where v.number=1 and v.type='E'

Select object_Name(i.object_id) as [name]
,p.rows
,Convert(varchar(50),@PageSize * SUM(total_pages)) + ' KB' as [reserved]
,Convert(varchar(50),@PageSize * SUM(CASE WHEN a.type <> 1 THEN a.used_pages WHEN p.index_id < 2 THEN a.data_pages ELSE 0 END)) + ' KB' as [data]
,Convert(varchar(50),@PageSize * SUM(a.used_pages - CASE WHEN a.type <> 1 THEN a.used_pages WHEN p.index_id < 2 THEN a.data_pages ELSE 0 END)) +  ' KB' as [index_size]
,Convert(varchar(50),@PageSize * SUM(total_pages-used_pages)) +  ' KB' as [unused]
FROM sys.indexes as i
JOIN sys.partitions as p ON p.object_id = i.object_id and p.index_id = i.index_id
JOIN sys.allocation_units as a ON a.container_id = p.partition_id
JOIN sys.tables t ON i.object_id=t.object_id
Where i.type<=1 and a.type=1
and
t.type='U' and is_ms_shipped=0
Group By i.object_id,p.rows
GO
Set statistics time off