Newcastle is a city located in Washington. With a 2020 population of 12,151, it is the 77th largest city in Washington and the 2694th largest city in the United States. Newcastle is currently growing at a rate of 1.37% annually and its population has increased by 17.06% since the most recent census, which recorded a population of 10,380 in 2010. Spanning over 4 miles, Newcastle has a population density of 2,731 people per square mile.
The average household income in Newcastle is $165,302 with a poverty rate of 4.87%. The median rental costs in recent years comes to $1,741 per month, and the median house value is $691,400. The median age in Newcastle is 38.7 years, 39.2 years for males, and 38.1 years for females. For every 100 females there are 96.8 males.