The static and dynamic behavior of a developed electrothermal fabric was studied using an electrothermal model that considers the following fabric parameters: thermal conductivity coefficient, specific heat capacitance, fabric mass, and initial temperature. An experiment was set up to measure the average temperature of the knitted fabric of ordinary materials, namely wool, cotton, and acrylic. These materials were knitted with silver-coated conductive yarns in three loop densities each at an applied electric power of 4 W. The calculated coefficient of determination is greater than 0.98, and the fit standard error is smaller than 1.11. Therefore, the analytical equation could accurately model the electrothermal characteristics of the thermal fabrics under an applied electric current and compute the temperature at a certain time for the same fabric using known parameters.