It is a commonly asked question that how much storage amount i have for my Google Sites site. Well, it very as Google offers Google Sites at various levels from free to paid version of Google Apps. So quota, file uploading limitation, number of page and site creation are different.

 For Sites created under: http://sites.google.com/site/
- Site quota: 100Mb/site
- Pages per site: unlimited
- Max attachment size: 20Mb

Google Apps: (former known as Standard or Free Edition)
- Quota per domain: 10Gb
- Max attachment size: 20Mb
- Unlimited (limit is five new sites per week per user)*
- Pages per site: unlimited
- Site quota: N/A (quota is tracked at the domain level)

Google Apps for Work
- Max attachment size: 50Mb
- Sites per domain: unlimited (Limit is five new sites per week per user for Trials and recently registered domains)*
- Pages per site: unlimited
- Site quota: N/A (quota is tracked at the domain level)
- Quota per domain: 10Gb + 500Mb multiplied by the number of paid users
Note: Google Apps Unlimited is same storage, file and site creating limits as Google Apps for Work

Google Apps for IPS
- Site quota: 100Mb/site
- Pages per site: unlimited
- Max attachment size: 20Mb

Google Apps for Education
- Quota per domain: 100Gb
- Max attachment size: 20Mb
- Sites per domain: unlimited
- Pages per site: unlimited
- Site quota: N/A (quota is tracked at the domain level)

How much number of sites i can create in Google Sites

*You can create unlimited sites per domain but it may take some time before you or even your domain admin is eligible for create unlimited sites. There are following few conditions applied:

  1. If you are with less then 6 users under your Google Apps domain, you can create an unlimited number of sites per domain after the equivalent of six monthly user subscriptions. Until that time, your limit is to create 5 sites per week.
  2. If you are more then 6 users under your Google Apps domain, you can create an unlimited number of sites per domain after the first full month billing cycle. It may requires few days after the cycle ends for system updates. Until then, the limit is creating five new sites per week per user. If you have reached the limit and get "Sorry you can not create more sites at this time," wait a couple of days and try again.

Related FAQ
Q. I am running of space for my site which i created under sites.google.com/site/, can i buy additional storage?
A. No, Google does not offer additional storage or sale storage for Google Sites. You can start using Google Apps for Work which offer 10 GB of storage and after that you can move your site or copy site to Google Apps domain and enjoy 10 GB of storage for your site.
Q. I did not find what i was looking for Google Sites?
A. You can Ask your Google Sites Question directly from Google Sites Expert team.