Counting every other row - DSUM? SUMPRODUCT?

I have a report where I need to create a calculation to sum every other cell in a column.  I was successful in getting results using the following formula =SUMPRODUCT((MOD(ROW($AM$11:$AM$500),2)=0)*($AM$11:$AM$500)) .  I also tried using =MOD(ROW(AM9),AS2)=0.

Using the first formula I was able to match the sum that I have by selecting the cells manually for all of the even numbered row in the range.  The second formula resulted in a 0 sum.   My problem is that I have numbers in the odd cells that I need to sum as well. Is it possible to use either of the formulas from above to get the results without having to manually select the cells?
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Ken ButtersCommented:
When entering this formula...

Press : CTRL+SHIFT+ENTER.  This will enter the formula below as an array formula.


barry houdiniCommented:
This version sums every other row starting with the first row in the range (in your case that will be the odd rows)


change the 0 to a 1 and it sums all the others


Note: the extra ROW function makes the formula more robust in that it will still give the correct results even if you add or delete rows in the worksheet

regards, barry

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
jmac001Author Commented:
Thanks Barry that fixed the problem.  I also had deleted rows and it throw the calcuation off so the report is now accurate with the added Row function.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft Excel

From novice to tech pro — start learning today.