I recently got asked this in class..one of the students had received a file from one of their customers (who had hidden some of the rows) and he wanted to only get the total for the visible, filtered rows. I tried a couple of things – including Visible Cells only (F5 – Special – Visible Cells only) but eventually what I found worked was using a variation of the subtotal formula…
=subtotal (109, range)
You can view the video below here.