Download Your Google Data

Google makes it real easy to download your email, calendar, contacts and most other data you have in their services.  To submit your request, follow the "Download your Data" link at this support page, select one or more (or all) of the products you want and answer a few questions on what format and how you want to save it.  It takes from a few minutes to several hours depending on how much data you're asking to export.

https://support.google.com/accounts/answer/3024190