Vehicular seat including a weight determining system for obtaining an indication of the weight of an occupying item in the seat includes a seat support structure, a cushion arranged on the seat support structure, the cushion having an upper surface over which the occupying item is situated during occupancy of the seat and being arranged to deflect downward during occupancy of the seat, and a sensor system arranged to sense the downward deflection of the cushion and convert the downward deflection into an indication of the weight of the occupying item. The sensor system may include an elongate cable, a cable support retaining a first end of the cable and a displacement sensor arranged at a second end of the cable for measuring linear variations of the cable which are convertible into the indication of the weight of the occupying item.