heres a easy calculator i just found http://www.tarotschool.com/Calculator.html
for example: i want to check for my current year since my birthday has not happened yet, i check for last year
long description http://accessnewage.com/articles/Tarot/lottar2.htm short description http://www.cosmictarot.co.uk/discover-your-tarot-year-card/
this site has more descriptions http://thetarotroom.com/tarot-growth-cards/ but you have to know your number, use calc above