A system and method for automatically recalibrating a resistive touch screen. The resistance of a resistive touch screen layer is subject to change over time, while the resistance of silver bus bars connecting the resistive touch screen layer to analog-to-digital converter (ADC) elements is not. Calibration tables are used to convert an ADC count representing a voltage across the entire touch screen to an ADC count representing a percentage drop across the touch screen layer only. A new calibration table is generated periodically by measuring the current through the touch screen and using this to determine a new voltage drop across the touch screen layer only.