Incrementing a range

[Bella08]

Hi,

I am trying to workout monthly volatility using the stdev function. I Have a column with the number of work days in each month.

So for example if I have 22 days of returns in jan, 20 in feb, 22 mar and so on. I want each row to go stdev(A1:a22) then stdev(a23:a42) then stdev(a43:a64) but without having to type the numbers manually. I want it to point to the number of days volume and increment the range by the correct number of working days.

I have tried using offset, but I can get it to work. As I have 15 year worth of data manually typing this in is very timely.

Any help would be gratefully appreciated.

Ewan

[BadlySpelledBuoy]

Here's my approach. Note this uses an array formula so needs to be confirmed with Ctrl+Shft+Ent rather than just Ent.

BSB.