Sum every third row

[georgecomstock]

Col v2:v4533 contains decimal numbers
I want, in Col w to sum every three cells from col v.
So cell W4 would contain the sum of V2:V4
W7 would contain the sum of V5:V7
W10 would contain the sum of V8:V10 and so on until the end of the column.
Please can anyone help. Thank you.

 

[steve the fish]

Try this in W4 and copy down:

=IF(MOD(ROW(),3)=1,SUM(V2:V4),"")

 

[georgecomstock]

I did, and it worked, like a charm! Thank you for your elegant solution and fast response.