If i go to top i want to know how much free ram i have without touching the filecache, used ram is used ram. >Despite I know these hairy implementation details

If i go to top i want to know how much free ram i have without touching the filecache, used ram is used ram. >Despite I know these hairy implementation details about the ways OS kernel manages physical memory, I don’t really care. I do, and obviously everyone that implements top and htop etc.