This paper investigates the factors that affect economic growth in developed nations, such as the U.S., the United Kingdom, France, Germany, Australia and others. It also includes developing countries such as Brazil, Russia, India, China and South Africa (BRICS). This study incorporates several independent variables to examine their influence on economic growth in these two groups of nations. The study looks at contributing factors for economic growth, such as life expectancy, primary education, secondary education, expected import, expected export, population growth rate, FDI level, and public expenditure, using macro-level data from two sources: the World Bank and the Organization of Economic Co-operation and Development (OECD). The results show that the education levels in a population determine a country’s human capital, which heavily influences economic growth.