Calculating the relationship between two people is often a confusing issue. There are lots of tables and charts that try to alleviate this situation. For instance, you can read my article of "What Is Second Cousin Once Removed?" However, the terminology can be a bit confusing, and trying to mentally figure the relationships can be a bit taxing. After all, what is a third cousin four times removed? For the majority of us who wrestle with these relationships, there is a simple solution: use your computer!
There are a number of computerized "cousin calculator" programs available, including web-based tools as well as programs for Windows, MS-DOS, and Macintosh OS X. The only place I know of to find all of these in one place is iRoots.net.
To calculate your "cousinship" to someone else in your extended family, go to http://www.iroots.net/tools/cusncalc/.