The present invention relates to a stress-measuring device (10) and method for determining a level (15) of stress of a user (1), in particular long-term stress. The stress-measuring device (10) comprises an input interface (12) for receiving a skin conductance signal (11) indicating the skin conductance of the user (1), the skin conductance signal (11) over time forming skin conductance trace data (13). The stress-measuring device (10) further comprises a processing unit (14) for processing the skin conductance trace data (13), the processing unit (14) adapted to determine, over at least a portion of the skin conductance trace data (13), values of a rise time (tr) between at least two different points of the skin conductance trace data (13), to determine a frequency distribution of the rise time (tr) values, and to determine the level (15) of stress of the user (1) based on the determined frequency distribution.
