The Cook Partisan Voting Index (Cook PVI, usually just PVI) has become one of the standard measures of assessing a political unit's partisan lean, one often seen in diaries on this website. Though it is not too difficult to figure out/understand (indeed, it's to the Cook Political Report's credit that they are as transparent/open to outside input about it as they are), to make the process of calculating it easier I put together an easy and intuitive PVI calculator using Microsoft Excel. More info after the jump.
To use it, all you have to do is enter the Democratic and Republican national popular vote of the two elections for which you are calculating the two-party average, as well as those for the units which you will be comparing to this average. An example, using the 2012 results for New Hampshire, both statewide and by county, can be seen below:
Also, if you want to try the calculator out for yourself, it can be downloaded here:
https://drive.google.com/...
Feel free to add any comments/critiques about the calculator, particularly ways it could be improved!