Is 750 mb of Wi-Fi a lot on an iPhone 4S?

I'm on a new contract for my iPhone 4S and I've only just realised that my Wi-Fi is limited! I only have 750mb! Is this a lot? I'm always connected to Wi-Fi when I'm at home, even when I'm not using it. I only really use it for Facebook and Twitter which I check regularly throughout the day. I sometimes search the web to find out information. I very very rarely go on YouTube using Wi-Fi. Will my Wi-Fi get used up very quickly if I'm using it this often for these websites when I only have 750mb to use throughout the month?

Added (1). It is definitely Wi-Fi! I have 250mb of mobile data (which is the 3G) and then 750mb of Wi-Fi! Wi-Fi is not unlimited on my contract unfortunately! And I only just found that out.

I think you mean 3G, not Wi-Fi. Yes, 750MB of 3G is more than it sounds. My sister has 500MB of 3G on her contract and she's only gone over the limit once and it was only because we were on holiday.

You should have an unlimited amount of Wi-Fi at home, I imagine that you it says you have 750MB of 'internet', and this means 3G internet, being pulled over the mobile network.

Using your Wi-Fi at home uses NONE of this allowance, it's 'mobile data' or whatever it is on the iPhone that uses up the allowance, and 750MB is a lot, it would easily last you a month with your usage.
Facebook and Twitter use up barely anything.

Well Browsing And Email's Will Be More Than Sufficient!
But Youtube Videos And Download Of Songs, Games, Movies, Then It Will Go Within Few Hours!

Some mobile phone contracts come with the option of extra Wi-Fi which usually has a limit. This Wi-Fi limit you're confused about will be the amount of free Wi-Fi available from your network provider or mobile retailer at designated hot spots across the country. The amount of Wi-Fi you will be able to use on your own private home network will be unlimited.

For example, i currently have an iPhone 5 with 1GB of data and 1GB of Wi-Fi. The limit on my Wi-Fi means that when i'm in a place which offers Cloud Wi-Fi i can access it using my log in details unlimited, until i reach the 1GB cap on my Wi-Fi account - You will usually get an email or a text message when you begin to near this limit. Any Wi-Fi i use whilst at home or at work (private networks) do not count towards this 1GB limit and so i can download as much video, apps, games ect as i want without touching my Wi-Fi allowance.

That means that even though you have a 750MB Wi-Fi limit, while you're at home that does not count and you can browse as many pages and social network sites as you please. Just remember that when you're not in a Wi-Fi hot spot or at home and you connect to the internet you will be using your 250MB of data.

If you want to read more about it please have a look at our support page which might be able to help answer a few more of your questions. Here's the link: http://support.phones4u.co.uk/

Hope that helps.