Computer vision (CV) is a field of artificial intelligence (AI) that enables computers and systems to derive meaningful information from digital images, videos and other visual inputs. One of the applications of CV is studying the movements and gestures of hands. Hand gestures offer an inspiring field of research because they can facilitate communication and provide a natural means of interaction that can be used across a variety of applications. In this project, a virtual calculator is developed using OpenCV and the Mediapipe library. Virtual calculator performs the arithmetic operations by detecting hand movements and hand gestures using a webcam. In addition to this, a user interface was developed to show the results of virtual calculator.