People in Monaco have the longest life expectancy, with an average of 89.73 years, according to the CIA. Among countries with populations larger than 250,000, the life expectancy in Japan is highest, with 87 years for women and 80 years for men averaging out to 83.5 years, according to WHO.
Monaco is the world's second-smallest country. As of 2015, it has a population of about 30,500, according to the CIA. Though the average life expectancy is technically the longest in Monaco, the WHO excludes Monaco from the list because Monaco's small population skews the data.
Among countries ranked by WHO, the longest life expectancies are found among women in Japan and men in Iceland, with 87 and 81.2 years respectively. The population-wide average of 83.5 years in Japan is higher than the average life expectancy for men in any country on the WHO list.