Plainfield is a city located in Union County New Jersey. With a 2020 population of 50,091, it is the 17th largest city in New Jersey and the 788th largest city in the United States . Plainfield is currently declining at a rate of -0.23% annually but its population has increased by 0.57% since the most recent census, which recorded a population of 49,808 in 2010. Plainfield reached it's highest population of 50,464 in 2015. Spanning over 6 miles, Plainfield has a population density of 8,406 people per square mile.
The average household income in Plainfield is $77,210 with a poverty rate of 21.20%. The median rental costs in recent years comes to $1,212 per month, and the median house value is $257,200. The median age in Plainfield is 34.6 years, 34 years for males, and 35.4 years for females.