There are 3 elements to a google search results each has a different limit on whats is visible before truncation hides the rest. These limits are in pixels not characters, as an I is narrower than an M. These limits also vary across devise and other variables.
As Google does not counts characters but pixels of a page title or url you need to be able to test and measure different options so you can be sure that your page will show optimally as a Google search results. This tool is perfect for the job http://www.webshoptimizer.com/page-title-pixel-meter/
Try this Google SERP snippet optimization tool as a guide when creating your Title and Meta descriptions
https://totheweb.com/learning_center/tool-test-google-title-meta-description-lengths/
Test it using the url for this page
https://sites.google.com/catalystmdc.com/use-gsites-to-rank-for-kw/optimizing-urls-of-google-sites-for-click-thru-and-serps-ranking