A passenger detection device for a vehicle is provided with multiple load sensors, each of which detects a load on a seat of the vehicle within a predetermined detection range of the load sensor, and an ECU that determines passenger information of the seat. The ECU has at least one calculation range, each of which limits the detection range of each corresponding one of the multiple load sensors. The ECU determines the passenger information based on a detection data value of each load sensor, which is outputted from the load sensor and falls within the corresponding calculation range of the load sensor.