City · Washington
Newcastle, Washington
Newcastle, city, in King County, Washington. Newcastle had 13,128 residents on July 1, 2025 by the Census Bureau's estimate, up 0.9% since 2020; the 2020 Census counted 13,017 and the ACS 2020-2024 5-year estimates put it at 12,989 (±26). GEOID 5348645.
Residents, July 2025 estimate
13,128
Census Bureau estimate (no margin published)
2020 Census count: 13,017 · ACS 2020-2024: 12,989 ±26
Median household income
$160,278
±$25,737 (90% margin)
Washington: $98,141
Median home value
$1,205,600
±$65,046 (90% margin)
Washington: $564,600
Median gross rent
$2,369
±$66 (90% margin)
Washington: $1,760
Where is Newcastle and what county is it in?
Newcastle is a city in King County, Washington. It covers 4.4 square miles of land, 2,935 residents per square mile in 2020.
Newcastle is in the Seattle-Tacoma-Bellevue, WA metropolitan statistical area, which takes in 3 counties (Census Bureau delineation, July 2023).
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in Newcastle, and is it growing?
The Census Bureau estimates that 13,128 people lived in Newcastle on July 1, 2025, up 0.9% since 2020, slower than Washington (+3.8%). The 2020 Census counted 13,017 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 12,989 (±26).
| Measure | Newcastle | King County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 12,989 ±26 | 2,287,171 | +1,239 |
| Households | 5,416 ±272 | 941,054 | +912 |
| Average household size | 2.39 ±0.12 | 2.39 | −0.21 |
| Housing units | 5,723 ±258 | 1,003,284 | +1,013 |
Newcastle's population since 2000
From 7,737 in 2000 to 13,128 in 2025: up 69.7%. The 2000, 2010 and 2020 figures are census counts, each for Newcastle as it was drawn that year: a place that annexed land, or a community that has since incorporated, covered a different area then. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.
Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); Census PEP Vintage 2025 (SUB-EST2025, CO-EST2025); 2020 Census P.L. 94-171 · Check it at data.census.gov
Who lives in Newcastle?
The median resident of Newcastle is 37.5 years old; 19.9% are under 18 and 15.8% are 65 or older. The largest group is non-Hispanic Asian residents at 42.1%, then non-Hispanic white residents at 37.6%. 32.8% of residents were born outside the United States.
| Measure | Newcastle | King County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 37.5 ±2.0 | 37.4 | no clear change |
| Under 18 years | 19.9% ±2.5 pts | 19.5% | – |
| 65 years and over | 15.8% ±2.8 pts | 14.0% | – |
| Male | 48.1% ±2.9 pts | 50.7% | – |
| Hispanic or Latino (any race) | 4.5% ±2.1 pts | 11.0% | no clear change |
| White alone, not Hispanic | 37.6% ±4.5 pts | 52.9% | −16.6 pts |
| Black or African American alone, not Hispanic | 3.5% ±3.2 pts | 6.4% | – |
| Asian alone, not Hispanic | 42.1% ±5.1 pts | 20.5% | +9.2 pts |
| American Indian and Alaska Native alone, not Hispanic | 0.0% ±0.3 pts | 0.4% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0% ±0.3 pts | 0.7% | – |
| Two or more races, not Hispanic | 9.3% ±2.8 pts | 7.3% | – |
| Some other race alone, not Hispanic | 3.0% ±3.5 pts | 0.6% | – |
| Born outside the United States | 32.8% ±4.3 pts | 25.8% | no clear change |
| Speak a language other than English at home (age 5+) | 41.9% ±4.9 pts | 31.1% | – |
| Civilian veterans (age 18+) | 3.0% ±1.2 pts | 4.5% | – |
| With a disability | 8.7% ±2.3 pts | 10.3% | – |
| No health insurance coverage | 1.9% ±1.0 pts | 5.2% | −2.0 pts |
| High school graduate or higher (age 25+) | 97.4% ±1.4 pts | 93.8% | – |
| Bachelor's degree or higher (age 25+) | 68.5% ±4.1 pts | 56.7% | no clear change |
| Graduate or professional degree (age 25+) | 29.7% ±4.7 pts | 24.2% | – |
| Lived in the same house a year earlier | 83.1% ±4.6 pts | 83.3% | – |
| Moved from another state in the past year | 3.6% ±1.8 pts | 3.5% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov
What do households in Newcastle earn?
Half of Newcastle's 5,416 households earn less than $160,278 a year (±$25,737), against $124,746 in King County and $98,141 in Washington. In 2015-2019 it was $159,779 in 2024 dollars; the margins of error cannot tell the two periods apart. 5.9% of residents live below the poverty line.
| Measure | Newcastle | King County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $160,278 ±$25,737 | $124,746 | no clear change |
| Mean household income | $235,039 ±$32,932 | $176,799 | – |
| Per capita income | $91,506 ±$9,200 | $74,100 | no clear change |
| People below the poverty line | 5.9% ±3.2 pts | 8.6% | no clear change |
| Children under 18 below the poverty line | 1.8% ±2.3 pts | 9.7% | – |
| Households receiving SNAP | 3.5% ±2.3 pts | 8.2% | – |
| Households with a computer | 97.6% ±2.4 pts | 98.1% | – |
| Households with a broadband subscription | 96.6% ±2.3 pts | 95.1% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What does housing cost in Newcastle?
Owners occupy 61.0% of Newcastle's occupied homes and renters 39.0%. The median owner-occupied home is valued at $1,205,600 by its owner (±$65,046). The median renter pays $2,369 a month including utilities, and 45.9% of renters pay 35% or more of their income on rent.
| Measure | Newcastle | King County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $1,205,600 ±$65,046 | $859,900 | +$270,888 |
| Median gross rent | $2,369 ±$66 | $2,092 | +$137 |
| Renters paying 35% or more of income on rent | 45.9% ±10.4 pts | 37.5% | no clear change |
| Median monthly owner costs, with a mortgage | $4,000 or more | $3,273 | – |
| Owner-occupied homes | 61.0% ±4.5 pts | 55.4% | −14.8 pts |
| Renter-occupied homes | 39.0% ±4.5 pts | 44.6% | – |
| Housing units | 5,723 ±258 | 1,003,284 | +1,013 |
| Homeowner vacancy rate | 0.4% ±0.6 pts | 0.7% | – |
| Rental vacancy rate | 4.7% ±5.3 pts | 5.3% | – |
| Single-family detached homes | 57.5% ±3.7 pts | 50.0% | – |
| Mobile homes | 0.2% ±0.4 pts | 1.4% | – |
| Built 2020 or later | 1.6% ±1.3 pts | 2.1% | – |
| Built 2010 to 2019 | 30.3% ±4.6 pts | 14.2% | – |
| Built 1939 or earlier | 0.0% ±0.7 pts | 10.9% | – |
| Households with no vehicle | 10.2% ±4.5 pts | 11.2% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov
How many new homes is Newcastle building?
Builders took permits for 88 new housing units in Newcastle in 2025 (88 in single-family houses), 6.7 per 1,000 residents against 4.4 across Washington.
Counts of units in permits a local office issued; not every permitted unit is built. A year marked with months was reported for part of the year.
Source: Building Permits Survey, annual place files 2019-2025, U.S. Census Bureau · Census Building Permits Survey
How do people in Newcastle work and get to work?
57.8% of Newcastle's workers drive alone and 30.2% work from home. The average trip to work takes 27.9 minutes. The unemployment rate in 2020-2024 averaged 5.6%.
| Measure | Newcastle | King County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 64.2% ±4.2 pts | 69.9% | – |
| Unemployment rate | 5.6% ±1.7 pts | 4.8% | no clear change |
| Drove alone to work | 57.8% ±6.1 pts | 50.4% | – |
| Carpooled | 4.6% ±2.9 pts | 7.0% | – |
| Public transportation | 2.5% ±1.4 pts | 6.8% | – |
| Walked | 2.4% ±1.5 pts | 4.3% | – |
| Worked from home | 30.2% ±5.7 pts | 29.2% | +21.2 pts |
| Mean travel time to work | 27.9 min ±2.5 | 27.6 min | no clear change |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What census tracts are in Newcastle?
2 census tracts lie mostly in Newcastle, and 5 more reach into it (2020 census blocks). Their median household incomes run from $155,855 (Tract 250.05) to $213,309 (Tract 247.03).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 250.05King County | 6,352 | $155,855 |
| Tract 247.03King County | 4,075 | $213,309 |
| Tract 250.01King County | 5,599 | $167,917 |
| Tract 247.04King County | 4,214 | $180,625 |
| Tract 251.01King County | 6,208 | $128,447 |
| Tract 249.04King County | 2,909 | $250,000 or more |
| Tract 252.02King County | 4,609 | $120,359 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 block assignment files (tract share = share of the tract's census blocks in Newcastle) · Census block assignment files
How does Newcastle compare with other places in Washington?
By the Census Bureau's July 2025 estimates, Newcastle is the 2,649th-most populous of the 19,476 U.S. incorporated places that have one and the 78th-most populous of 281 in Washington.
Newcastle ranks 35th of 387 places in Washington with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population, July 2025 estimate | 78th | 281 |
| Growth 2020-2025 (PEP) | 143rd | 203 |
| Residents per square mile | 96th | 394 |
| Median household income | 35th | 387 |
| Per capita income | 16th | 393 |
| Median home value | 11th | 384 |
| Median gross rent | 38th | 351 |
| Poverty rate | 218th | 281 |
| Bachelor's degree or higher | 14th | 382 |
| Median age | 247th | 394 |
| Owner-occupied share | 289th | 388 |
| Work from home | 36th | 307 |
| Travel time to work | 177th | 394 |
Newcastle's figures with every place in Washington (CSV)
Every place in Washington, sortable · Compare Newcastle with other places
Source: PlainCities ranks computed from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed
How reliable are the figures for Newcastle?
10 of the 57 figures for Newcastle on this page carry a coefficient of variation over 40% and are marked with a ring: they come from a small sample, so read them as rough.
The American Community Survey samples about one household in eight over five years, so every figure is an estimate with a 90% margin of error (shown under each value). A ring marks an estimate whose coefficient of variation is over 40%. A change is called only when the gap between the two periods is larger than their combined 90% margin (the square root of the sum of the two squared margins), the Census Bureau's test. How to read a margin of error.
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026): margins of error as published · ACS technical documentation
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections
Not on this page: crime, weather and schools for Newcastle are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' public schools in Newcastle.