How much free disk space to add or subtract to maintain 30% free space

Copper Contributor

I was wondering if any math/excel gurus could lend me hand with this problem I'm working on.

 

I'm trying to use Excel to create a report that would tell me how much free space to add or remove to maintain 30% free space on a disk.

 

I attached an example of what I've been working on. Please let me know if there is anymore info I could provide. I appreciate any feedback.

1 Reply

Perhaps something like this

=(0.3*B2-D2)*(D2<0.3*B2)

in attached file