Strange tech problem with Excel

[Supersadie]

My excel workbooks are doing something strange and different at the moment.
Every time I open a book or change any cell, it takes ages to open or recalculate anything, even if it's just one letter in a word and gives a message at the bottom 'calculating (4 threads): X%'
Many thanks.

[xlnitwit]

Hi,

It sounds like you have a workbook open with some complicated volatile formulas. Does it happen if you only have a new workbook open?

[Supersadie]

I do have a 4.7Mb workbook open. I've just closed it and the other books are now opening quickly. Thank you.
What should I do with my big workbook? Chop it into one sheet per book?

[xlnitwit]

That is not particularly large, even for Mac Excel. I suspect you have some volatile functions like OFFSET, INDIRECT, TODAY in that workbook? If so, I'd suggest trying to revise them to use non-volatile alternatives such as INDEX.

[Supersadie]

Yes. I have an offset in one. Thanks for your help.