The general transmissivity law of ground vibrations was studied, and a user-friendly methodology for determining the behavior of vibrations generated in any rock mass is proposed. The study was based on a single blast in a trench excavation, analyzing the vibration components recorded from two fixed loca-tions. The attenuation law and the main variables according to the legal requirements, frequency and peak particle velocity (PPV), are defined with this novel method, achieving a high confidence level in a simple manner. The proposed approach can also have an important impact in terms of reducing the potential consequences of vibrations for the surrounding construction and achieving the required definition of rock mass. Reducing the cost and time in many projects where blasting techniques are applied is particularly useful for the design of future blasts.