Google Calendar Embed - WordPress

To embed a Google Calendar in your WordPress page or post:

1. Activate the Google Calendar Widget & Short Code plugin
2. Create or navigate to the page or post where you'd like to embed the calendar
3. Paste the Google Calendar embed code directly into the page or post (this is located in your Google Calendar Settings and starts with <iframe>)
4. Save or update the page and you will notice that the embed code is replaced with shortcode [gcal src=...]

http://wordpress.org/extend/plugins/wpgcal/