Black Diamond Flag

Black Diamond

County:
King County
County Seat:
No
Area (mi²):
6.598
State:
Washington

Black Diamond is a city located in King County, Washington. Black Diamond has a 2026 population of 7,757. Black Diamond is currently growing at a rate of 6.67% annually and its population has increased by 60.07% since the most recent census, which recorded a population of 4,846 in 2020.

The median household income in Black Diamond is $141,383 with a poverty rate of 2.1%. The median age in Black Diamond is 38.1 years: 39.8 years for males, and 34.9 years for females. For every 100 females there are 109.0 males.

7.8K
Total Population
1,176
Density (mi²)
485 6.67%
Growth

Black Diamond Population

Black Diamond Population

Data after 2023 is projected based on recent change

Year ↓
Population
Growth
Annual Change
20267,7574856.67%
20257,2724857.15%
20246,7872984.59%
20236,4893545.77%
20226,13556110.06%
20215,57472815.02%
20204,8461513.22%
20194,7853417.67%
20184,444-4-0.09%
20174,448180.41%
20164,430300.68%
20154,400471.08%
20144,353471.09%
20134,306390.91%
20124,267671.6%
20114,200491.18%
20104,150150.36%
20003,97000%

Median Age

Overall: 38.1 years
Female: 34.9 years
Male: 39.8 years

Black Diamond Adults

There are 4,478 adults, (609 of whom are seniors) in Black Diamond.

Sex Ratio

Female: 2,852 (47.8%)
Male: 3,109 (52.2%)

Demographics

The racial composition of Black Diamond includes 67.82% White, 17.9% Asian, and smaller percentages for other race, Black or African American and multiracial populations.

Population by Race

Race
Population ↓
Percentage (of total)
White4,04367.82%
Asian1,06717.9%
Two or more races66211.11%
Other race1652.77%
Black or African American240.4%
Race
Population ↓
Percentage (of total)
Two or more races2784.66%
Other race1312.2%
White470.79%
Asian160.27%
Race
Population ↓
Percentage (of total)
White3,99667.04%
Asian1,05117.63%
Two or more races3846.44%
Other race340.57%
Black or African American240.4%

Black Diamond Marital Status

Economics and Income Statistics

Black Diamond 's average per capita income is $90,476. Household income levels show a median of $141,383. The poverty rate stands at 2.1%.

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$154,355-
Families$152,641$174,371
Households$141,383$166,104
Non Families$102,995$137,013

$90,476

Average Income

$141,383

Median Household Income

2.1%

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)