I have an Excel sheet where I sum hours to get the total amount of my work.

It works without problems, but if I add an automatic filter I'd like the calculations to be done only on the portion of data shown by the filter – and right now it keeps on counting, even the hours "hidden" by the automatic filter.

Is there any way to obtain this?

I'd like to use plain Excel, without programming and VBA scripts.

Probably the question lacks of details, but if someone with more expertise can help with comments to improve the question I'll be glad to do it.