Calculate YTD based on known month

[mkvassh]

I want to calculate Year To Data in B1 based on some data in C1 to N1. The monthnumber is located in cell A1.

There is of course several ways to do this, but is there a simple and easy formula one can use.

[mkvassh]

I found one on my own. This one will do the job.

=SUM(C1:INDEX(C1:N1,A1))

[DonkeyOte]

Assuming the month number corresponds - ie if A1 is 1 this means C1 only then

=SUM(C1:INDEX(C1:N1,A1))

edit: snap

[mkvassh]

Thank you DonkeyOte