According to UN Department of Economics and Social Affairs, by 2030 there will be around 8.5 billion people in the world. This was listed in 2015 and now we are in 2019. Here are some statistics for the largest populations in terms of cities and countries. China and India are the only countries with more than a billion inhabitants. Since I live in the United States, I included the largest states. The largest city continues to be New York City, the largest populated state is California. The other statistics were taken from 2017 and 2018.