Algonquin is a city of 30,067 people in Illinois. Owners hold 88% of the housing stock. That is roughly 61% ahead of the Illinois median. That puts it in the top 3% of US cities for household income. Median household income runs $134,525, well clear of the $82,259 US median. 6,791 more people live here than in 2000.
At a glance
Wealthier
median household income $134,525, above the US median
US median: $82,259
Older
median age 41.4
US median: 38.9
More educated
44% hold a bachelor's degree
US average: 36%
Stable housing
home values roughly flat, inflation adjusted
US median home: $376,019
Unique to this place
What stands out about Algonquin
What changed most since 1990
Population11,705 → 30,067(+157%)US over the same years: +35%
Median age31.0 → 41.4(+10.4 years)US over the same years: +6.0 years
White share96.7% → 72.7%(−24.0 pts)US over the same years: −17.8 pts
Algonquin's population equals 9.6% of McHenry County's. Its number of households without a car equals 16% of the county's. Its number of people who work from home equals 15% of the county's.
Shares are "alone or in combination": a person with both Medicare and Medicaid counts in each, so categories overlap and do not sum to 100%.
Section 09 · Service history
Veterans
Veterans by period of service, 2024
Gulf War (2001 or later)25.2%(330)
US avg: 26.4%
Gulf War (1990s)25.4%(333)
US avg: 24.3%
Vietnam era28.6%(375)
US avg: 33.1%
Korean War10.9%(143)
US avg: 4.5%
World War II2%(26)
US avg: 1%
Share of the 1,311 veterans here. A veteran who served across eras counts in each, so shares can total more than 100%. Peacetime-only service is included in the total but not shown as an era.
BAR + DOT: THIS PLACE · TICK: US AVERAGE
Over time
Algonquin, decade by decade
Algonquin population, inflation-adjusted income and home value, education, and diversity by year
Year
Population
Median household income
Median home value
Bachelor's degree+
Diversity score
1990
11,705
$128,800
$323,049
32.9%
8.0
2000
23,276
$145,241
$354,312
38.7%
19.8
2010
30,046
$138,832
$411,000
43.6%
38.2
2020
29,700
$133,105
$324,948
44.0%
51.9
2024
30,067
$134,525
$351,000
43.6%
55.2
Census years come from the decennial census and the latest year from the American Community Survey, so part of any change between those two rows can reflect the different surveys. Dollar figures are adjusted for inflation to 2024 dollars; a figure ending in "+" was at the Census Bureau's reporting cap that year. The diversity score runs from 0 to 100; see how it's calculated.
