What is the U.S. prison population?It's higher than any country's in the world, including China's and Russia's. The U.S. is now home to a quarter of the world's inmates, despite making up just 5 percent of the global population. The total number of federal, state, county, and local prisoners has ballooned from 320,000 in 1980 to about 2.4 million today — and taxpayers spend more than $80 billion a year to keep all these people locked up.