A developed country is a sovereign state that has a high quality of life, developed economy and advanced technological infrastructure relative to other less industrialized nations. Most commonly, the criteria for evaluating the degree of economic development are gross domestic product (GDP), gross national product (GNP), the per capita income, level of industrialization, amount of widespread infrastructure and general standard of living. Which criteria are to be used and which countries can be classified as being developed are subjects of debate. A point of reference of US$20,000 in 2021 USD nominal GDP per capita for the International Monetary Fund (IMF) is a good point of departure, it is a similar level of development to the United States in 1960.
The Human Development Index (HDI) is a statistic composite index of life expectancy, education, and per capita income indicators, which are used to rank countries into four tiers of human development. A country scores a higher level of HDI when the lifespan is higher, the education level is higher, and the gross national income GNI (PPP) per capita is higher. It was developed by Pakistani economist Mahbub ul Haq and was further used to measure a country's development by the United Nations Development Programme (UNDP)'s Human Development Report Office.
The Human Development Report (HDR) is an annual Human Development Index report published by the Human Development Report Office of the United Nations Development Programme (UNDP).
Solomon Islands 
Papua New Guinea 
Afghanistan 
Gambia (average)
Guinea 
Burkina Faso, 
Eritrea 
South Sudan 
Chad 
Niger