Vehicular seat assembly includes a seat having a bottom portion and a back portion coupled at an angle to a rear portion of the bottom portion, a support structure arranged at least partially under the seat and to support the seat on a substrate at a plurality of locations including two rearward locations on opposite lateral sides of the seat and at least one forward location, and a weight measuring system arranged in connection with the support structure for determining an approximate weight of an occupying item of the seat. The weight measuring system consists of only one or two sensors, e.g., strain gage sensors, arranged at the rearward locations or only one or two sensors arranged at the forward location(s). Each sensor provides data relating to the force or pressure being applied at the respective location which is used to derive the approximate weight of the occupying item.