How Google calculates site load times in the data it exposes in Google's webmaster statistics? Is the calculation simply average time to get and receive the HTML content for a page? Actually, it's a Yes. It works as, Googlebot sends out the request and beginning from there, Google calculates the time it takes for them to see the request back. So it is almost like, the end-to-end time to deliver the page or deliver the data from the server. Google sees it from the view of Googlebot. Google has no idea how to calculate the time for any given user to deliver a page. So, Google sees only at Googlebot's perspective.