Summing every third column

[aheitner]

I have a spreadsheet that looks like:

Col 1: customer's name
Col 2: customer's revenue, month 1, componant a
Col 3: customer's revenue month 1, componant b
Col 4: customer's total revenue, month 1 [=Col 2+Col 3]
Col 5: customer's revenue, month 2, componant a
Col 6: customer's revenue month 2, componant b
Col 7: customer's total revenue, month 2 [=Col 5+Col 6]
....
repeat

I would like to insert a column that provides the total revenue fo
each customer [i.e. the sum of Col 4, Col 7, Col 10...etc.].

The headings on Col 4, 7, 10, etc. are all "Montly Total". Is there
way to easily request the sum of every third column? Or a functio
that will look up "Monthly Total" multiple times across the entir
spreadsheet?

Each time I've tried to use a function, the function seems to look u
only the first instance of "Monthly Total".

Many thanks in advance.

-Andre

 

[Paul Corrado]

As long as Monthly Total is the header in each month's total then you can
use SUMIF

This formula is for the first row of data, which I assume is in row 2 with
the header in row 1. Adjust as necessary to fit your range and copy down


=SUMIF(B$1$1,"Monthly Total",B22)