The Human Development Index of the United Nations Development Programme is commonly used for international comparisons of the relative development status of whole countries.

This index combines three standard indicators:
1. Real GDP per person (gross domestic product divided by mid-year population), which adjusts the standard GDP according to country-specific purchasing power parity calculations
2. Adult literacy rate
3. Life expectancy

Adapted from World Health Organization. Terminology. A glossary of technical terms on the economics and finance of health services. Internet. Accessed December 18, 2015.