To optimize magnitude estimation for the earthquake early warning system around the Tehran region, different amplitude‐ and frequency‐based parameters, that is, predominant period (), characteristic period (), log‐average period (), and peak displacement () were analyzed in this article. All parameters were calculated directly from seismic records, with an epicentral distance less than 150 km, and within the initial 3 s of the P waves. The analysis of earthquakes in the magnitude range verified that the result of showed a consistent trend as compared with the global observations, and provided a robust estimate of magnitude for the dataset used in this research. In comparison with worldwide observations, the calculated and were underestimated, and there was no scaling relationship with the parameter. When combined with the global observations from Japan, Taiwan, and Italy, the results of and for the Tehran region produced optimized results.