When you formatting the disk, I.e in 4k Units(4096), or 1024, or 512Bytes
So actually the “template/formula” is not accurate, as the " 127775277056 " is bytes and reported Total
Disk-size 31311781 X 4096 = 128 253 423 616
Disk-use 28361875 X 4096 = 116 170 240 000
So in the end it’s 11.253 (11.3 ) but do to the " 127775277056 " i guess it only show 11.2
your sensor reports Total 31311781 Units on the Disk, and 28361875 Units used
1 Unit = 4096 Bytes
Smallest unit on a Disk( HD CD SSD) can contain 512Bytes(Called a Sector), been like that since the 70-80th when IBM took the lead of the HD Standardization
Now a days is the default When you format a Disk in i.e Windows " 4K unit" 4096Bytes ( a multiply of 512 )
1 Unit can only held information from 1 file
so if you have 1000 files that are only i.e 472 Bytes large each, each files will take up 4096 Bytes of space, if the disk is formatted with large 4096 Units … im sure you have seen this in windows ( File-Size vs File-size on disk )
This means i.e that those files total size are 1000x472 = 472.000 B
But on the Disk the they will occupy total of 1000x4096= 4 096 000 B … 10 times more(waste of space)
in early Days, But actually still ( as nothing has change on this parts ), there will beside waste “optimization of space”, also be a “performance” issue to take into consideration, beside “fault-tolerance” , when formatting a disk, as now you can format with 512 , Multiply to i.e 64K or 2MB , whatever supported for various supported OS/File-Systems