Newcastle Flag

Newcastle

County:
King County
County Seat:
No
Area (mi²):
4.435
State:
Washington

Newcastle is a city located in King County, Washington. Newcastle has a 2025 population of 12,505. Newcastle is currently declining at a rate of -1.01% annually and its population has decreased by -4.86% since the most recent census, which recorded a population of 13,144 in 2020.

The average household income in Newcastle is $239,714 with a poverty rate of 3.14%.The median age in Newcastle is 37.4 years: 36.2 years for males, and 39.1 years for females.

12.5K
Total Population
2,820
Density (mi²)
-128 -1.01%
Growth

Newcastle Population

Newcastle Population

Data after 2023 is projected based on recent change

Demographics

The racial composition of Newcastle includes 43.26% White, 39.54% Asian, 3.75% other race, and smaller percentages for Black or African American and multiracial populations.

Population by Race

Race
Population
Percentage (of total)
White5,60043.26%
Asian5,11839.54%
Two or more races1,53811.88%
Other race4863.75%
Black or African American2031.57%

Newcastle Marital Status

OverallMalesFemales0%10%20%30%40%50%60%70%80%90%100%

Married

Widowed

Divorced

Separated

Never Married

Economics and Income Statistics

Newcastle's average per capita income is $101,021. Household income levels show a median of $162,646. The poverty rate stands at 3.14%.

Families: A family includes the owner or renter of the home along with everyone related to them - whether through birth, marriage, or adoption. This includes relatives like spouses, children, parents, siblings, grandparents, and any other family members.
Households: A household includes all the people who occupy a housing unit (such as a house or apartment) as their usual place of residence.
Non Families: A nonfamily household is either someone living alone or when the owner/renter lives with people they aren't related to, like roommates.
Name
Median
Mean
Married Families$225,699-
Families$215,600$289,599
Households$162,646$239,714
Non Families$91,518$109,541

$101,021

Average Income

$162,646

Median Household Income

3.14%

Poverty Rate

Nearby Cities

Sources

  1. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  3. American Community Survey (2009 - 2013)
  4. Census QuickFacts
  5. Historical Populations of States and Counties (1790 - 1990)