Let's use this random spreadsheet to illustrate my problem.What I want to do is a sum of all Page Views (F) that contains the Category (B) named /Online Computers. Which formula can I use to do that?I wanted to Google it before asking here but I'm not sure how this is called.
Which formula sums all values from a column in a line that contains a specific word?
google spreadsheets;formulas
You can use the =SUMIF as MaryC says, or the =FILTER function that I usually prefer:  =SUM(FILTER(F2:F, B2:B = /Online Computers))The =FILTER function filters your data so that only rows matching B2:B = /Online Computers are included.See the example spreadsheet I've set up, and the Google spreadsheets function list.