6th largest of 19
Among Colorado’s 19 cities of 50,000+ residents, Thornton ranks 6th by population (147,766, July 2025).
Thornton is a city in Colorado. The Census Bureau estimates 147,766 residents in July 2025, compared with 141,867 counted in the 2020 Census. With 37 square miles of land, it had 3,884 people per square mile in 2020. These figures describe the city itself, not its county or metropolitan area.
Key indicators
Population
147,766
July 2025 estimate · Census Bureau
2020 Census population
141,867
April 2020 · Decennial Census
Change since 2020
+4.2%
April 2020 base to July 2025
Households
50,566
ACS 2020–2024 · Census Bureau
Population density
3,884 /mi²
2020 Census · 37 mi² of land
Median household income
$103,088
ACS 2020–2024 · 2024 dollars
Median home value
$517,500
Owner-occupied · ACS 2020–2024
Median gross rent
$1,895 /month
ACS 2020–2024
Poverty rate
7.0%
ACS 2020–2024
Bachelor’s degree or higher
32.8%
Adults 25+ · ACS 2020–2024
Foreign-born residents
14.0%
ACS 2020–2024
Hispanic or Latino residents
37.7%
ACS 2020–2024
Historical data
Pick an indicator to see its long-run evolution.
Population · annual estimates
2010–2025147,766▲ 24%
Census Bureau Population Estimates Program (Vintage 2020 for 2010–2019, Vintage 2025 from 2020).
Data summary
| Indicator | Value | Year and source |
|---|---|---|
| Population estimate, 2025 | 147,766 | Census Bureau, Vintage 2025 |
| Population estimates base, April 2020 | 141,869 | Census Bureau |
| Population, 2020 Census | 141,867 | Decennial Census |
| Population, 2010 Census | 118,772 | Decennial Census |
| Population, 2000 Census | 82,384 | Decennial Census |
| Land area | 36.5 mi² | Census Gazetteer 2024 |
| Median age | 34.7 years | ACS 2020–2024 |
| Per capita income | $43,571 | ACS 2020–2024 |
| Owner-occupied housing | 71.4% | ACS 2020–2024 |
| Unemployment rate | 4.5% | Civilian labor force · ACS 2020–2024 |
| Veterans | 6,669 | Civilians 18+ · ACS 2020–2024 |
Thornton in context
Comparable indicators for the city, California and the United States.
| Indicator | City | California | U.S. | Reference |
|---|---|---|---|---|
| Median household income | $103,088 | $95,470 | $80,734 | ACS 2020–2024 |
| Median home value | $517,500 | $539,400 | $332,700 | ACS 2020–2024 |
| Median gross rent | $1,895 /month | $1,761 /month | $1,413 /month | ACS 2020–2024 |
| Poverty rate | 7.0% | 9.4% | 12.5% | ACS 2020–2024 |
| Bachelor’s degree or higher | 32.8% | 45.7% | 35.7% | ACS 2020–2024 |
| Foreign-born residents | 14.0% | 9.8% | 14.1% | ACS 2020–2024 |
| Owner-occupied housing | 71.4% | 66.2% | 65.2% | ACS 2020–2024 |
| Median age | 34.7 years | 37.7 years | 38.9 years | ACS 2020–2024 |
Did you know? Thornton
Growing since 2020
The city gained 5,897 residents (+4.2%) from April 2020 to July 2025, 9th for growth among the state’s 19 large cities.
Two decades of change
The census counted 82,384 residents in 2000 and 141,867 in 2020, a +72.2% change.
Above the state income
Median household income is $103,088, +8.0% versus Colorado ($95,470); 7th of 19 large cities.
Home values
The median owner-occupied home is worth $517,500, 12th highest of the state’s 19 large cities.