lost space after formatting NTFS

[PC656]

I bought a new HGST 7K4000 drive before I started formatting it a ~3800 gb and when I started the format it then had ~3700 gb of space. I left the allocation unit size to default and enabled file and folder compression.
I just wanted to know I it was normal to loose a 100 gbs of space when formatting or if it was due to something else I did.

 

[ex_bubblehead]

Perfectly normal. All of the information required for the filesystem requires space of its own.

 

[USAFRet]

I bought a new HGST 7K4000 drive before I started formatting it a ~3800 gb and when I started the format it then had ~3700 gb of space. I left the allocation unit size to default and enabled file and folder compression.
I just wanted to know I it was normal to loose a 100 gbs of space when formatting or if it was due to something else I did.

Absolutely normal
A "4TB" drive is actually read as 3.7TB.

Gigabyte vs gibibyte
Base 10 vs Base 2
Human vs computer

http://wintelguy.com/gb2gib.html
https://en.wikipedia.org/wiki/Gibibyte