Rollup on condition?!

[Kosta_Kondraten]

I want to create a conditional rollup field that only calcualtes the sum of values that are marked as Completed (so there’s a column with a checkbox - I only want to calcualte the totals if the row has that checkbox selected with a tick) - Makes sense?

How do I do that? I know I can do that in Excel right? Can I do it in AirTable?

[OldHector]

Bumping this again, same issue. I need to be able to refer to the current record in order to create a useful rollup. So, rollup records in the linked table where linkedtable.field1 = thistable.field2.