Why Does My Itunes keep saying Over Capacity?

I Have a16 Gb iphone and i currently have 1,140 songs which takes up 8 gb total according to itunes, keep in mind that i have over 1 gb free, so i decided to add a few more songs and tried to sync but then it said over capacity by 302 mb i don't get it, How can i be over the capacity by 300 mb if i have at least 1gb available?/ can someone please explain this!

The phone can't be packed to capasity because it needs room for cache. Cache allows the phone to operate the programs it runs.

  • Why is my iphone over capacity? I only have like 9 apps and not even 100songs on it? I'm trying to add pictures to it but its saying its over capacity and its also going really slow, i've token out half of my apps and deleted most of my pictures too but nothing helps
  • Why does Netflix keep pausing and playing over and over? I'm using it on my iphone 4. And I have checked my connections over and over I've uninstalled reinstalled, signed in signed back and everything else that the troubleshoot website has recommend. And it's gotten annoying. It didn't start doing this as much until I updated the app before the ios 7 release. I'm currently using the trial for netflix and my laptop doesn't work so I can get it on anything but my phone.
  • Why does my iPhone keep saying this I'm trying to download the GTA 3 app and its a little over 400mb. I have 1.2gb free of space (more than enough) why won't it download! I've already deleted a ton of apps and pictures and still nothing. I'm getting mad! :/
  • Why does my iphone 5s keep on saying 'no service' i just got it about 20 mins ago? My dad just bought me an iphone 5s about 15-20 minutes ago. I just got home and wanted to call my friend but it said 'No Service'.So I asked my sister and she said her iphone was able to call and text immediately after her purchase. I would like to fix this problem by tonight if not tomorrow. I also tried the airplane mode method and it didn't work.