# MDX-How do I calculate sales for 12 Month to date?

Q: How do I calculate sales for 12 Month to date in MDX?

A: We have to assume that your date dimension last member represents last month. Then to get last 12 month we can use Lag function. Example:

SELECT [Measures].[Order Count] ON 0
, ClosingPeriod([Date].[Calendar].[Month], [Date].[Calendar].[All Periods]).Lag(12)
: ClosingPeriod([Date].[Calendar].[Month], [Date].[Calendar].[All Periods]) ON 1

Result:

 Order Count August 2003 1,759 September 2003 1,783 October 2003 1,779 November 2003 1,888 December 2003 2,272 January 2004 1,944 February 2004 2,030 March 2004 2,108 April 2004 2,127 May 2004 2,385 June 2004 2,374 July 2004 976 August 2004 (null)

Now to get sum of sales query could be :

WITH MEMBER [Measures].[Last 12 Mth Order Count] AS
SUM(
ClosingPeriod([Date].[Calendar].[Month], [Date].[Calendar].[All Periods]).Lag(12)
: ClosingPeriod([Date].[Calendar].[Month], [Date].[Calendar].[All Periods])
, [Measures].[Order Count]
)
SELECT [Measures].[Last 12 Mth Order Count] ON 0