How much space does ios7 take up? Can i delete ios6 to free up more space?

I only have iphone 4 with 8GB and ios6 took up 2GB and now how much GB does ios7 need? Is there any way i can delete ios6 to free up more space? How do i get more storage?

You need atleast 3.1 gb, you can delete music you don't listen to, pointless apps, photos&videos other then that there's not really anyother ways to get more storage, that i know atleast.

  • Will buying more iCloud space let me download more apps, songs, and photos? So i have deleted apps that i don't really need and deleted songs i don't listen to but still there's not enough space to even take a photo, A pop up comes up that says to manage my icloud storage. Would purchasing more icloud storage allow me to download more apps and have more songs and pictures on my iPhone 4 from sprint? It is an 8gb i think.
  • Why does my small amount of photos take up so much space? On my iPhone 7, I have only 76 pictures/videos. When I click manage storage, it says that they take up 1.3 gb of space, while my friends have hundreds of photos but when they click manage storage, it only takes up a couple hundred mb. Why do the photos take up so much space on my phone or how can I fix this problem?
  • Why does my Messages app on my iPhone take up so much space? I have an iPhone 5 on iOS 7. I've deleted all except 3 of my messages, yet it is taking up 1.3 GB of my phone's space. Why is it taking up so much space and how do I fix it?
  • Why does my iphone say my photos take up so much space? I have only like 300 photos in my iphone and it still says that it takes up 4GB and its frustrating since i've already deleted over 700 photos and my phone still does indicate much change of my storage space. Could it be that there's some hidden location all my photos have been saved or something?