How to check quantity of indexed keywords?

Aside from using AHrefs - is there a "free" way to check for how many keywords have been indexed? I am assuming that it is possible in Google Search Console but I haven't figured out the method

Do you guys have a more "accurate" version than my method below (which might actually be accurate?)

site: domain .com 

^ this pulls up a message from Google like this:

 About 1,170,000 results (0.43 seconds) 

How accurate is that or is there "another more accurate method?"