How long will 2GB of data last?

My mum has ordered me an iPhone 5, but the package deal only has 2GB data allowance. I'm a bit worried because the deal on my current phone is unlimited data. I use the internet a lot; I'm on twitter, tumblr, youtube, ao3 and different sites almost all the time. I'll also use iMessage and SnapChat and Kik quite a lot on the iPhone too. Will 2GB last me? What will it allow me per day? Will I go over my usage?

It lasts me a month. But it depends on how much you use internet, youtube, apps, etc outside of wifi. When on wifi you use no data so you just need to limit your use when off wifi. If you don't have wifi at your house than that 2gbs won't last very long but I'm guessing you do have it.

2GB is Enough for Browsing but if you Download anything like music or video then 2gb is not good enough. I only browse sites stay connect on different social sites so 1 GB is enough for me (I use 2G Connection).
If you use 3G or 4G then its not good enough it last maybe at least 15-20 days. It Depend how you use.