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 2026 population of 13,035. Newcastle is currently declining at a rate of -0.14% annually and its population has decreased by -0.84% since the most recent census, which recorded a population of 13,145 in 2020.

The median household income in Newcastle is $160,278 with a poverty rate of 5.93%. The median age in Newcastle is 37.5 years: 36.6 years for males, and 38.7 years for females. For every 100 females there are 92.5 males.

13K
Total Population
2,939
Density (mi²)
-18 -0.14%
Growth

Newcastle Population

Newcastle Population

Data after 2023 is projected based on recent change

Year ↓
Population
Growth
Annual Change
202613,035-18-0.14%
202513,053-19-0.15%
202413,0721951.51%
202312,877-10-0.08%
202212,887-85-0.66%
202112,972-173-1.32%
202013,1451361.05%
201912,2864974.22%
201811,789270.23%
201711,7621631.41%
201611,5992312.03%
201511,3681751.56%
201411,1931581.43%
201311,0352412.23%
201210,7942472.34%
201110,5471671.61%
201010,396300.29%
20007,73700%

Median Age

Overall: 37.5 years
Female: 38.7 years
Male: 36.6 years

Newcastle Adults

There are 10,400 adults, (2,047 of whom are seniors) in Newcastle.

Sex Ratio

Female: 6,747 (51.9%)
Male: 6,242 (48.1%)

Demographics

The racial composition of Newcastle includes 42.05% Asian, 38.98% White, 3.63% other race, 3.53% Black or African American, and smaller percentages for and multiracial populations.

Population by Race

Race
Population ↓
Percentage (of total)
Asian5,46242.05%
White5,06338.98%
Two or more races1,53411.81%
Other race4713.63%
Black or African American4593.53%
Race
Population ↓
Percentage (of total)
Two or more races3282.53%
White1811.39%
Other race780.6%
Race
Population ↓
Percentage (of total)
Asian5,46242.05%
White4,88237.59%
Two or more races1,2069.28%
Black or African American4593.53%
Other race3933.03%

Newcastle Marital Status

Economics and Income Statistics

Newcastle 's average per capita income is $100,366. Household income levels show a median of $160,278. The poverty rate stands at 5.93%.

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$207,147-
Families$206,277$288,358
Households$160,278$235,039
Non Families$71,750$110,235

$100,366

Average Income

$160,278

Median Household Income

5.93%

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)