How do I find where JDK is installed on my windows machine?

I need to know where JDK is located on my machine.

On running Java -version in cmd, it shows the version as ‘1.6.xx’.
To find the location of this SDK on my machine I tried using echo %JAVA_HOME% but it is only showing ‘JAVA_HOME’ (as there is no ‘JAVA_PATH’ var set in my environment variables).