The Human Development Index (HDI) is a country-level measure of social welfare based on national values for average life expectancy, rates of adult literacy and school enrollment, and gross domestic product (GDP) per capita. Since HDI is based entirely on national averages it can provide only limited information about distribution within countries. The distribution of access to key resources is an important determinant of the effect of health, education and income on both individual well-being and on the aggregate well-being of a population as a whole. This paper makes a case for the importance of inequality to measuring social welfare; presents an original alternative to HDI that includes the distribution of health, education, and income in each country; and reports the results of this inequality-adjusted HDI for 46 countries.