Why is only 223.57 GB seen of my 240 GB SSD

[DWall9]

I am about to install an OS on to this series 530 240GB SSD. I first look at it in a host Win 7 environment via Disk management. Disk Management states only 223.57 GB is unallocated. 240 - 223.57 = 16.43 GB unaccounted for. That is too large of an overhead wouldn't you agree? Is it possible to reclaim most of that 16.43 GB and how do you?

Also, since I am installing a fresh OS onto the SSD is there any prep work I need to do to the SSD?

[glussier]

Same reason why you are not getting 1TB on your C: drive. Hard-drive manufacturer calculator KB, MB, GB etc with a 1000 factor instead of 1024 like normally used. So, no, you can't get more from your 240GB drive.