The needle penetration force is an important factor which has substantial effect on the stitch quality and the amount of possible damage to the fabric. In this regard, developing predictive models for calculating the amount of needle force is related to the important factors of fabric and needle. In this paper, first the predictive model of Lomov for calculating the needle penetration forces is briefly introduced. Then, the necessary steps to improve this model are presented. For this purpose, the amount of needle penetration force is obtained as a function of the needle tip diameter. In the next step, three different cases of Lomov's model for possible contact between the needle and the fabric are introduced. In addition to the resultant forces from movement of the warp and weft threads, the required rupture force is calculated. Finally, the maximum needle penetration force calculated from our predictive mathematical model is compared with an experimental study for three fabric types.