I'm trying to make a Google Sheets that will list my total expenditures in the form of recurring fees/subscriptions. I've successfully enabled the basic 'SUM=(C2:C24)', but I would like to add a caveat; periods of time. To clarify, some of my expenditures are every three months and some are every month. I would like to take this into account. An example:
I pay Last.fm $9 every 3 months for their premium service. While I could simply change the price column to $3/month, I would like to be able to account for this using the formula. I am not familiar with formulas in Excel or Google Sheets beyond being able to read them.