Why is my sheet running so slow??

It's not just when I run a macro, it's all the time.

do you have some very nested formulas in every single cell? that would do it. I read a recent article, it is the way excel set up. even if you only change value in one cell, it will recalculate the whole spreadsheet. it is just how excel works. if you have a lot of different nested formulas that link to each other, that will do it. even if it is less than 1 MB. i have a spreadsheet that is 25mb, and it takes me 30 mins to clear contents on one out of the 18 tabs