Find the number of (Portal) Roles in an organization

You can find this through the User Interface or using the API via tools like Workbench.

User Interface

Please navigate to the "System Overview" setup section ( https://instance.salesforce.com/setup/systemOverview.apexp?setupid=SystemOverview ) and check the "Portal Roles" section.

Note: The Portal Roles box in the system overview page shows the usage data and limit for total partner portal, Customer Portal, and Communities roles. Also, please note that the Roles in the Territory Hierarchy (partner, Customer Portal and Communities roles) count towards this limit.

Workbench

Open Workbench. Click on "Info" and select "Metadata Types & Components". Then you can select "Role" as metadata type. The number of roles will display in the "Components" folder.

Note: The Workbench shows also the number of Roles in the Role Hierarchy.
More information about the Role metadata type: Metadata Types
 

The Portal Roles count can also be found using SOQL if necessary. Please use the following queries and add the results together to get the total count.

SELECT Count() FROM UserRole where PortalAccountId != Null
SELECT Count() FROM UserRole where PortalAccountOwnerId != Null