Nevermind. It looks like the physical disks are 500GB in size, which makes sense.
We have a Dell PowerEdge server with a PERC 6/i controller. There are three 1TB physical disks. I created a RAID 5 array, but it looks like there is only 1TB of usable space after initializing the RAID 5 virtual disk. Does this sound wrong? I've Googled what the size should be, and I think it should be 2TB of usable space, not 1TB?
3 1TB physical disks in RAID 5 set with only 1 TB usable space sound wrong? 
Using a Dell PERC 6/i controller.