In Diskutility I can see that I only have 249.1 GB of free disk space where I should have 1.27 TB free disk space.
But the 'Turn off FileVault' button is grayed out. Now I would like to turn FileVault off again as it is using 1.8 TB disk space. I turned on FileVault prior to leaving at Apple authorized dealership to replace battery.
Very happy with performance and disk space until battery needed replacement. I have a 'Vintage' MacBook Pro early 2011 that I upgraded with 2 TB Samsung SSD and 16 MB memory.