The proliferation of IoT networks across various sectors necessitates robust Trust Management mechanisms for secure and reliable operations. This paper proposes a Multi-Attribute Decision Making (MADM)-based approach for trust score calculation in IoT Trust Management. This solution addresses limitations of existing methods by considering multiple attributes and providing a comprehensive evaluation of trustworthiness. The methodology computes a device's trust score by integrating factors such as Cyber Risk, Ease of Access, and Security Level using a weighted sum-based calculation. The Analytical Hierarchy Process (AHP) to determine the factors’ weights is utilized, contributing a novel approach to IoT Trust Management. Furthermore, this approach includes dynamic trust score updates throughout the device's lifetime, accommodating changes in the device's Cyber Risk for accurate trust assessment. A trust score penalization mechanism for devices below a predefined threshold is also introduced, enabling prompt risk mitigation. A simulated assessment, considering varying numbers of IoT devices, evaluates the effectiveness of the proposed methodology. By addressing limitations and introducing innovative components, the proposed MADM-based approach enhances security, reliability, and overall performance of IoT networks. This research advances trust management in IoT and provides valuable insights for developing secure and trustworthy IoT ecosystems.