How are the quotas calculated?

Accounts - Max number of accounts your organization can have at any point in time

Users - Max number of users your organization can have at any point in time

Surveys - Max number of surveys your organization can have at any point in time. This includes archived surveys. Deleted surveys will not be included in quota.
Story Sites - Max number of story sites your organization can have at any point in time. 

Stories  - Max number of stories your organization can have at any point in time. 

See Quotas page