A touch display device is provided which includes a display panel for displaying an image, and a touch screen panel disposed on the display panel and configured to sense at least one touch. The touch screen panel includes a touch substrate at which the touch can be generated; sensing electrodes provided on the touch substrate and spaced apart from one another, each of the sensing electrodes being formed of a piezoresistive material having a resistance value that varies according to an applied force; and a touch processor electrically connected to the sensing electrodes. The touch processor extracts a touch coordinate based on time constants of sensing signals applied to the sensing electrodes, and calculates a touch force of the touch based on resistance values of the sensing electrodes.