The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.
One of a set of tools we're offering as a way of saying thank you for being a part of the community.
If you're concerned about the performance impact of having that much compressed, then you should see about getting more disk space. Add a volume or something.
Since you only show 64K of deleted space not yet purgeable, I wouldn't worry about the purgeable delay settings.