Here’s how to get Schema Version of Active Directory from command line or using PowerShell:

Using dsquery:

dsquery * “CN=Schema,CN=Configuration,DC=lab,DC=local” -scope base -attr objectversion

Using PowerShell:

Get-ADObject (Get-ADRootDSE).schemaNamingContext -properties objectVersion

Conversion table for objectVersion:

13 = Windows 2000
30 = Windows 2003
31 = Windows 2003 R2
44 = Windows 2008
47 = Windows 2008 R2
56 = Windows Server 2012

Nice script for PowerShell Active Directory Schema Update Report.

Reference and Schema objectVersion attribute.