Previously established models for electromagnetic shielding effectiveness in metallized textiles have limitations in accurately forecasting the shielding effectiveness of metallized nonwovens. In response, this study embarks on a exploration aimed at formulating a mathematical model capable of predicting the electromagnetic shielding effectiveness specific to metallized nonwoven fabrics. By converting the nonwoven parameters into suitable woven parameters and optimizing the existing models, a refined mathematical model is proposed. To validate the feasibility of the model, experimental verification is conducted using three commercial copper coated nonwoven polyester fabrics CuPET10/20/30. At the 1.5 GHz frequency point, both the values derived from the newly prediction model and the experimental observations exhibited satisfied compatibility across all three samples. However, at the 3 GHz frequency point, a noticeable disparity was observed for CuPET10, with the experimental SE value measuring 47.78 dB, deviating from the SE range projected by the predictive model, which encompassed values between 41.18 dB and 45.76 dB. In contrast, the experimental SE values of CuPET20 and CuPET30 at 3 GHz stood at 57.8 dB and 68.56 dB, respectively, closely aligning with the model's predicted SE range of 53.6 dB–63.7 dB and 60.02 dB–70.65 dB, respectively. The two-sample p-test was performed in the frequency range from 0.5 GHz to 3 GHz. The results reveal a significant level of agreement between the average shielding effectiveness (SE) value predicted by the proposed model and the measured SE value from samples CuPET20 and CuPET30, which p value are 0.16 and 0.06.