Row A1 - AB1 are different years, 2001, 2002, etc.
In row B1 - BB1

Hmmm...

Those ranges don't make sense.

Do you mean that in every other cell there is a year number and you want to
sum the values to the immediate right of the year number cell?

Something like this:

2002 | 10 | 2009 | 20 | 2010 | 5 | 2002 | 50 |

The sum for year 2002 would be 60, 10+50.

Is that what you have?

--
Biff
Microsoft Excel MVP


"Lindsey" wrote in message
...
I understand how sumif work veritically, but what if I want to sumif by
rows
instead of columns?

Row A1 - AB1 are different years, 2001, 2002, etc. In row B1 - BB1, there
are numbers. I would like a formula that sums up the different years.

I would transpose the data, but it needs to be in this format to work with
another software.

Thanks in advance for your help!