This tool calculates how hard it is to type a word. It takes into account how far your fingers need to move to type a key, which hand is used to type a letter, how long words are, and repeated letters.
http://sakabako.github.io/word-cost/
Ideally it would use the scoring system from this paper: http://web.mst.edu/~tauritzd/courses/ec/fs2003/project/Walker.pdf