I have only used up 4 GB of my iPad but it is showing it as 8 GB used up.

Hello Sayamsethi,

After reviewing your post, I have located an article that can help with iOS usage. It contains helpful advice:

See how much storage you've used on your iPhone, iPad, and iPod touch

If your device is near its capacity or you get an alert that your storage is full, you can remove some of your less used content to make room for more.

View storage usage on your iOS device

Tap Settings > General > Usage > Manage Storage to see the amount of space each app and its content takes on your device.

Tap an app for more detailed information about its usage.

Depending on the app, you might be able to delete some of the app's content, or delete the app and all of its content.

View storage usage for your iOS device in iTunes

When you connect your device and select it in iTunes, you'll see your usage by content type:

• Audio: Songs, audio podcasts, audiobooks, voice memos, and ringtones
• Video: Movies, music videos, and TV shows
• Photos: Camera Roll contents, Photo Stream, and Photo Library
• Apps: Installed apps
• Books: iBooks books and PDF files
• Documents & Data: App content such as contacts, calendars, messages, emails, and their attachments, Safari Offline Reading List, and files that you've created in your apps
• Other: Settings, Siri voices, and other system data

Hover your mouse over the content type for more information about usage.

iTunes displays how much space the selected songs, videos, audiobooks, and apps use in the status bar on the bottom of the screen. You can also see this information by selecting an item and then choosing File > Get Info. The size is available in the Summary tab.

You can transfer or sync content to your computer from your device. If you want to remove certain types of content from your device, learn how to manually manage content using iTunes.

Learn more

Learn more about storage capacity on OS X and iOS.

Thank you for contributing to Apple Support Communities.

Cheers,

BobbyD