Steps Involved:
  1. Open SharePoint 2010 Management Shell by going to Start | All Programs | SharePoint | Microsoft SharePoint 2010 Products | SharePoint 2010 Management Shell (Run as Administrator).
  2. Run the following script.

Powershell Script:

 
 
##Get the total number of user profiles using SharePoint 2010 web service in powershell
$uri="http://serverName:10736/sites/ECT2/_vti_bin/UserProfileService.asmx?wsdl"

## Web Service Reference - http://Site/_vti_bin/UserProfileService.asmx
$userProfileWebServiceReference = New-WebServiceProxy -Uri $uri -UseDefaultCredential 
$count=$userProfileWebServiceReference.GetUserProfileCount()
Write-Host -ForegroundColor Green "Total Number of user profiles: " $count


Output:

output.jpg