There is no easy way to get a total count of workflow rules in the organization. You can create a list view for all workflow rules, then page through the list until you reach the end. The total count would then be # of pages * page size + final page size.
There is no way that you get the org directly, but you can pull the count using workbench. using REST explorer with Get(), /services/data/v45.0/tooling/query/?q=Select+Id+From+WorkflowRule
using REST explorer with Get(),
/services/data/v45.0/tooling/query/?q=Select+Id+From+WorkflowRule
Here is a query of all fields for this object: When quering FullName or Metadata, can only pull 1 record at a time.
Without those two fields, can get all WF rules like so: Or just get the total count: