The DNA Painter Shared cM Tool is an excellent resource for helping to establish relationships based the amount of cM shared with your matches. Their crowdsourced databases offers valuable insights which you can use to determine a range for different relationship types. To make this tool more easily accessible I added a button to the Ancestry DNA match page which links to the appropriate page on the Shared cM tool, available now in Genea Research Tools.
When you activate DNA Painter Shared cM Tool Button, on the Trees and Ethnicity tab of a DNA match a button will be added which opens the DNA Painter Shared cM Tool with the matches shared cM.
DNA Painter Shared cM Tool Button is available in Genea Research Tools for Google Chrome, it can be installed in one click from the Chrome Web Store: Click here to install Genea Research Tools from the Chrome Web Store