IMP points allow you to compensate for the variation in bridge hands when playing socially without duplicate hands. This calculator takes input on the declaring team contract, high card points (HCPs), and tricks taken and determines the score you should get vs what you did get. The result is "IMP Points". If they are positive, you played the hand well, and if negative....well, you never stop learning in bridge! The support website (accessed with the info symbol on the top left) explains how to use the app and includes sample scoring sheets for you to play with friends.