In particular, strategies and activities of countries with large economies on e-government can affect the global economy and other dimensions related to the economy. Therefore, measurement and analysis of e-government performances of countries with large economies is of great importance. In this context, in research, e-government performances of 19 major economies at the country level in G20 group were measured with the SD (Standard Deviation) based COPRAS method over the latest and current E-Government Development Index (EGDI) component values for 2020. In research, firstly, it was determined that the most important EGDI component for countries was the "Telecommunication Infrastructure Index" with SD method. Secondly, according to SD-based COPRAS method, it was found that first three countries with the highest e-government performance were South Korea, England and Australia, while first three countries with the lowest e-government performance were India, Indonesia and South Africa. In research, average e-government performance of countries was also measured, and it was observed that countries with higher performance than average e-government performance value were USA, Germany, Argentina, Australia, France, England, Italy, Japan, Canada, Russia and Saudi Arabia. According to this finding, it has been evaluated that countries that are below average e-government performance value should increase their e-government performance in order to increase their contribution to global economy. Thirdly, in terms of method, it was concluded that EGDI can be explained by SD-based COPRAS method according to sensitivity, discrimination and correlation analyses.