When I look throw GParted, it shows my home folder using 30.27 GB:
The Disk Usage Analyzer shows 13.3 GB:
And the properties show 26.0 GB:
So, what's the real usage of my home folder?
The correct usage is the one you see in GParted. According to the properties window, some contents are unreadable. It is also likely that there are symlinks, hidden folders, backup files, etc - giving the varied readings in Disk Usage Analyzer and Folder Properties.