To display a Google Calendar, Google Map or other iframe content, use a short code, enclosed in square brackets.
[iframe src="" width="100%" height="500"]
Please keep width=”100%”, as this will fill the available space on most devices and screen widths. The height value is set in pixels only; you can change this to suit your needs.
Copy only the URL/link from the iframe code you got from Google.
Paste the URL into the src attribute of the short code.
Be careful to paste inside the “” quote marks at src=””
Result: