Semiconductive polymer composites are used in a wide range of sensors and measurement devices. This paper discusses the development of a model and a new theoretical formulation for predicting piezoresistive behavior in semiconductive polymer composites, including their creep behavior and contact resistance. The relationship between electrical resistance and force applied to the piezoresistive force sensor can be predicted by using the proposed theoretical formulation. In order to verify the proposed formulation, the piezoresistive behavior of Linqstat, a carbon-filled polyethylene, was modeled mathematically. In addition, some experimental tests, such as thermo gravitational analysis and SEM, have been performed on Linqstat to find the volume fraction and size of carbon particles, which are essential for modeling. In addition, on a fabricated force sensor using Linqstat, a force versus resistance curve was obtained experimentally, which verified the validity and reliability of the proposed formulation.