Human development index i.e. the HDI rate is a measure created by the United Nations to measure the well being of a country. The HDI is formulated to be a composite statistic of life expectancy, education and income indices.
The index is calculated for each country making use of the life expectancy, education and income indices for that respective country. Once the HDI for each country is calculated it is used to rank the countries in the four tiers of human development.
The formula to calculate the HDI has seen only a few minor changes but the purpose for the formulation remains the same.
There is another HDI form called the inequality adjusted HDI which is the HDI once the adjustment in regards with inequality has been made. In the list where the countries are ranked as per their HDIs Norway occupies the top place with an HDI of 0.955.
It is followed by Australia and then USA with the HDI for the countries being 0.938 and 0.937 respectively. The HDI also helps the countries in determining the steps via which the state of well being of its population can be improved. Other countries in the list of highest HDI countries are Netherlands, Germany, and New Zealand etc.