Dynamically calculate variance over 2 last months

[mariussmintina]

Hi,

I have some data in the attached form.

The columns represent the sum of sales per month by country. Each run will have an additional month of data.

The last column is supposed to calculate the variance between this month and the previous month. But i cannot use a formula to calculate it as new months are added.

Do you have a suggestion on this issue? How can I dynamically select the 2 columns and calculate the month to month variance?

Thank you ! 

[binuacs]

@mariussmintina Is the column names going to be 1, 2 or the actual month names?

[binuacs · Accepted solution]

@mariussmintina One way of doing this

[mariussmintina]

Hi, 

Thank you so much this works well!