I understand overhead and all that, but I was given an iPad Mini 2 for Christmas. The box says 16 GB but iTunes says 11.89 is the capacity. I added up the information on Apps in the Storage panel in Settings and it came to just under 3.9 GB, yet it says "6.9 GB Used" and 4.8 GB available. 6.9 used?? I hardly have anything on it, no videos, no music, no photos, and I add up the storage sizes as shown in the unit itself and it only comes to 3.9. iTunes says "Other" is taking up 1.75 GB" so I deleted a bunch of apps and data and synced and NOW iTunes reports 4.04 GB Used but OTHER has grown to 1.93 GB! So by deleting a bunch of apps and data and adding nothing, "Other" grew by nearly a quarter gig? This is like having a Ferrari with a one-gallon gas tank. On top of that the gas tank is "shrinking". By contrast by iPod Touch 32GB states that it has an over 29GB capacity. So the overhead on 32GB is less than three GBs but the overhead for 16GB on an iPad is over 4GB? This is all maddening and I don't understand what's really going on in there.