Sum every third cell formula

[Rellsunn]

Hi!

Trying to figure out why my formula does total correctly. I have hidden cells so can't auto sum. Need to calculate every 3rd cell.

Formula I have is:

=SUMPRODUCT($H8:$H$1263*(MOD(ROW($H$8:$H$1263),3)=1)) - but it's not coming to the $2.59M total I need only $342K.

Image shows first cell H8 to total then add every third cell (white not grey)...

Thank you!

[Phuocam]

MOD(ROW(H8),3)=2

Try:

=SUMPRODUCT($H8:$H$1263*(MOD(ROW($H$8:$H$1263),3)=2))

[Jonmo1]

How about

=SUMIF($G$8:$G$1263,"",$H$8:$H$1263)

[Rellsunn]

Amazing! That did the trick Phuocam. Appreciate it.