In the United States, the average human life expectancy is 79.5 years. Life expectancy varies from country to country, and it depends on a multitude of factors. The United States ranks 42nd worldwide for life expectancy.
The country with the longest life expectancy on average is Monaco, where citizens tend to live to be in excess of the age of 80. The country with the lowest life expectancy is Chad. In this location, the average person lives just under 49.5 years. Current worldwide numbers for average life expectancy are calculated assuming that economic and health conditions of all countries remain the same. Actual life expectancies fluctuate depending on a variety of variables.