Conditional averages (AVERAGEIF, AVERAGEIFS, or other option?) - excel

Question

Perhaps it's just been a long week, but I can't think of how to get a pretty simple average.
Here's my data (two columns):
1/3/1994 1165
1/4/1994 1162
1/5/1994 1133
1/6/1994 1133
1/7/1994 1138
1/10/1994 1143
1/11/1994 1118
1/12/1994 1150
1/13/1994 1171
1/14/1994 1177
1/17/1994 1161
1/18/1994 1162
1/19/1994 1121
1/20/1994 1112
1/21/1994 1129
1/24/1994 1136
1/25/1994 1124
1/26/1994 1118
1/27/1994 1127
1/28/1994 1133
1/31/1994 1088
2/1/1994 1055
2/2/1994 1051
2/3/1994 1071
2/4/1994 1079
2/7/1994 1054
2/8/1994 1079
2/9/1994 1079
2/10/1994 1089
2/11/1994 1074
2/14/1994 1083
2/15/1994 1068
2/16/1994 1075
2/17/1994 1071
As you can see, it's a column of dates (that continue until Sept. 9 2015, so it's long), and another of price. I am just trying to get the averages for January each month, of each year (i.e. Jan 1994, 1995, 1996 ... 2015, then Feb 1994, etc).
Here's the table I plan on using the formula in:
2007 2008 2009 2010 2011
January
February
March
April
So, in the cell right of "January" and below "2007", I want the average of prices that are in Jan, 2007.
I tried using this (again, my data starts in A1 and B1):
=AverageIfs(B:B,year(A:A),1994,month(A:A),1) (regular and as array), but it doesn't work - I keep getting the error "The formula you typed contains an error." (I'd really prefer this to be a formula, rather than a VB solution)
Thanks for any ideas!
Edit: In the mean time, I have created two helper columns, that are just the Month() and Year() of each row of data. Then I can use =AverageIfs(B:B,[month helper range],1,[year helper range],2007). Is there a way to do this without a helper column though?

Answer 1

Try this
=AVERAGE(IF(YEAR(A:A)=1994,IF(MONTH(A:A)=1,B:B,""),""))
entered as an array formula (CTRL-SHIFT-ENTER). If you want to use the month as text you could use
=AVERAGE(IF(YEAR(A:A)=1994,IF(TEXT(A:A,"mmmm")="January",B:B,""),""))
Hope that helps

Answer 2

assuming your data has a header: "Date" and "Price" in cells A1, B1.
assuming your data begins in A2 = "1/3/1994" and B2 = 1165
C1 = "Month"
D1 = "Year"
C2 = =TEXT(A2,"Mmmm")
D2 = =YEAR(A2)
Copy Cells C2+D2 down ...
I place your new table in:
H2 = "January"
H3 = "February"
... etc.
I1 = 1994
J1 = 1995
... etc.
I2 = =AVERAGEIFS($B:$B,$C:$C,$H2,$D:$D,I$1)
and copy that formula throughout the table.
Cheers!

Answer 3

Yes, you can use AVERAGEIFS() and you should. This is about a thousand times faster than the accepted answer:
=AVERAGEIFS(B:B,A:A,">="&DATE(1994,1,1),A:A,"<"&DATE(1994,2,1))
You can even do it this way for a more concise formula, but I believe it raises problems for non-USA users because of their date format settings:
=AVERAGEIFS(B:B,A:A,">=1/1/94",A:A,"<2/1/94")

Answer 4

I don't know if this is the most concise solution, but it works. You can use SUMPRODUCT as follows:
=SUMPRODUCT((MONTH($A:$A)=1)*(YEAR($A:$A)=1994)*$B:$B)/SUMPRODUCT((MONTH($A:$A)=1)*(YEAR($A:$A)=1994))
What this is essentially doing is summing the values in column B based on the two criteria, and then counting the number of rows that matched the criteria and dividing by that number.
For each row, the MONTH and YEAR conditions evaluate to either 1 (true) or 0 (false) and then those two values are multiplied with the value in column B, resulting in column B's value if both conditions are true, or 0 if one or both conditions are false.

Answer 5

This solution requires to use in the "table with the results" the number of the month instead of the names of the month
It also assumes that the "table with the results" starts at F2 (see picture)
Then use this formula:
=IFERROR(AVERAGEIFS($B:$B,$A:$A,">="&DATE(G$2,$F3,1),$A:$A,"<="&EOMONTH(DATE(Q$19,$P20,1),0)),"N/A")
The formula shows “N/A” if there are no prices for the period (Year/Month), if you want to see blank then replace it with “”
Small changes done to your sample data to work with several periods