Another feature has graduated the Hangouts with Extras class and is now a core part of the Google+ Hangouts experience. As of today, you can now place free calls anywhere in the U.S. and Canada right inside your Hangout box.

In the past few months, we’ve graduated two widely-used features from Hangouts with extras to the main Hangouts experience: screensharing and Google Docs. Today, we’re excited to announce that we’re graduating a third and very popular feature — the ability to call a phone number from Hangouts. Calls to the US and Canada are free, and international calling rates are super, super low.

How low, you ask? According to Google’s current calling rates, calls to France and Germany will cost $0.10, India $0.02, and Mexico $0.15. You can check out their rate calculator to determine the current charges to other countries around the world.

Once inside a hangout, all you have to do is click the “invite” button and then the “+telephone” link. Enter the number you want to call and click “add.” You can only dial one number at a time.

The original Hangouts with Extras class included screensharing, Sketchpad, and Google Docs support. Earlier this month, Google Docs graduated and is now a core part of Hangouts. Hangout participants can collaboratively edit documents at one time.