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.

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, Native American, Native Hawaiian or Pacific Islander and multiracial populations.

Population by Race

White

Asian

Two or more races

Other race

Black or African American

Native American

Native Hawaiian or Pacific Islander

Race	Population	Percentage (of total)
White	5,600	43.26%
Asian	5,118	39.54%
Two or more races	1,538	11.88%
Other race	486	3.75%
Black or African American	203	1.57%
Native American	0	0%
Native Hawaiian or Pacific Islander	0	0%

Newcastle Marital Status

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