These are the places I trust to analyze where I stand and comeback to see what progress I have made.
1) Alexa Rank: https://alexa.com
2) SEOmoz Rank:
You can check at moz.com or any other free sites like : https://www.seoreviewtools.com/bulk-seomoz-authority-checker/
3) Ahrefs Score: Check your score at https://ahrefs.com/backlink-checker
4) Google Page Speed: https://developers.google.com/speed/pagespeed/insights/
All these tools will tell you how much traffic are you going to get from Google search engines. Improve on any of these and you will see an improvement in traffic and hence Earnings.