The USA currently has the second highest rate of incarceration in the world, with over 700 people in jail per 100,000 population. Approximately 85% of countries have a rate lower than 300 prisoners per 100,000 population.
There are about 2.2 million total prisoners in the USA. This number is difficult to determine exactly because US prisoners are kept in a variety of different facilities, including federal and state prisons, county jails, military prisons, juvenile detention facilities and civil commitment centers.
The country with the next highest prison population is China with about 1.7 million. However, China has four times the total population of the USA. Together, the United States, China and Russia hold half the world's total prison population.
More about prisons: