ArpadCalc
ArpadCalc is a program to calculate your rating compared to your opponent. If you know your opponents rating it will show your estimated rating, otherwise you can still see the difference between your and your opponents rating (just enter ‘0’ for “Opponents Rating”). ArpadCalc can be downloaded on the download page.
Screenshot of ArpadCalc 0.1
The Elo rating systemThe Elo rating system was devised by Arpad Elo and is a statistical system whereby chess players can measure their progress and compare their playing strength with other players. The higher your rating, the better you are. People who start playing chess usually have a rating of about 800 elo, club players around 1500, Grandmasters are rated 2500 and higher and the world champion is rated around 2800 elo.