In embodiments of angular contact geometry, touch input sensor data is recognized as a touch input on a touch-screen display, such as a touch-screen display integrated in a mobile phone or portable computing device. A sensor map is generated from the touch input sensor data, and the sensor map represents the touch input. The sensor map can be generated as a two-dimensional array of elements that correlate to sensed contact from a touch input. An ellipse can then be determined that approximately encompasses elements of the sensor map, and the ellipse represents a contact shape of the touch input.