Recent cyberattacks targeting critical energy infrastructures illustrate the significant importance of resiliency during survive, sustain, and recovery phases of the underlying system. Motivated by this observation, the paper aims at introducing a quantitative framework to measure the survivability of Cyber-Physical Systems (CPSs) against systematic cyberattacks targeting the power grid topology. In the proposed Cyber-Physical Resilience-based Survivability Metric (CP-RSM), the concept of Survivability Margin (SM) is introduced to observe the system’s ability in preserving the functionality of its crucial components. Available Generation (AG) and Network Accordant Connectivity (NAC) are taken into consideration to measure Power-side Survivability (PsS). Moreover, Cyber-side Survivability (CsS) is quantified based on the ultimate potential damage to the power grid based on alerts received from different security devices. Using the proposed metric, the system operator can perform corrective actions such as unit re-dispatching or system reconfiguration to minimize the damage. Effectiveness of the proposed CP-RSM is evaluated based on the PJM 5-bus test system.