Last year I found this 'Elder Index', which is defined as: "The Elder Index shows how much income single elders and elder couples need to be secure in their own homes based on their location and need for health care and other assistance in retirement."
In looking at it, my interpretation is that it is the minimum these folks think retirees need to not be needy in retirement. There is a separate report for each state. the UMASS Gerontology Institute
has copies Retirement and economic security - University of Massachusetts Boston
Also with copies is the Wider Opportunities for Women website, with additional features, but you need a free sign in to view WOW - Wider Opportunities For Women - Elder Index Landing