How to calculate space "entitites" size

[Dario Rigolin]

I have to migrate my Confluence installation to Altlassian Cloud. But my backup entities.xml is bigger than 200MB limit. I don't want to do a single space migration, I would like at least to remove couple of spaces from the main instance and import all other space using single file restore.

[Dario Rigolin]

I did export of single space and check the size of things insides the zip.

[Nic Brough -Adaptavist-]

There's no simple way to even approximate how large the file will be, you would have to read every page to see its size and attachments etc. 

I would make a temporary copy of your system, export it, then delete a space and export again, then compare the file sizes.  That will tell you how big that one space is in the export.  Then remove others and export again to see their sizes.