Round Lake is home to 18,628 people in Illinois. The population has roughly tripled since 2000, adding 12,786 people. That puts it in the top 5% of US cities for household income. That is roughly 34% ahead of the Illinois median. 77% of homes are owner-occupied. Density works out to 3,350 people per square mile.
At a glance
Wealthier
median household income $111,977, above the US median
US median: $82,259
Younger
median age 36.1
US median: 38.9
More educated
42% 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 Round Lake
What changed most since 1990
Population3,549 → 18,628(+425%)US over the same years: +35%
White share85.4% → 44.5%(−40.9 pts)US over the same years: −17.8 pts
Adults with a bachelor's degree7.6% → 41.5%(+33.9 pts)US over the same years: +15.3 pts
Round Lake's population equals 2.6% of Lake County's. Its number of households without a car equals 0.8% of the county's. Its number of veterans equals 1.1% 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)18.2%(48)
US avg: 26.4%
Gulf War (1990s)35.6%(94)
US avg: 24.3%
Vietnam era23.9%(63)
US avg: 33.1%
Korean War0%(0)
US avg: 4.5%
World War II0%(0)
US avg: 1%
Share of the 264 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
Round Lake, decade by decade
Round Lake 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
3,549
$74,285
$196,566
7.6%
32.1
2000
5,842
$105,749
$251,388
21.3%
53.6
2010
18,289
$109,754
$323,966
33.7%
76.8
2020
18,721
$100,054
$258,528
40.4%
82.3
2024
18,628
$111,977
$278,600
41.5%
82.0
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.
