Yesterday Google announced their Speed Scorecard, a tool for website owners to measure the impact of their site speed on their earnings and revenues. This is aimed at advertisers but can be used by anyone over here.
You can first plugin your domains and see how fast they load based on a 4G or 3G connection:
John Mueller explained that this uses a similar process to the other speed tools:
There's a bit more if you click the (i) link for help: "Included Sites: The Speed Scorecard covers a subset of sites from the CrUX Report which provides speed data for popular URLs that are known by Google's web crawlers." You can still test your site manually though!
— John ☆.o(≧▽≦)o.☆ (@JohnMu) February 27, 2018
Then they have this tool on the bottom that shows you how much more you can make in revenue if you increase your speed just a little bit. Here is the tool:
Forum discussion at Twitter.