Decatur, Illinois Demographics
Population trends, housing costs, income, commuting, and health, all on one page.
Decatur, IL Population Density Map and Area Scores
Area Score
Health, income and education, each graded from F to A+. Explore interactive maps for deeper analysis.
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C
Health Below average
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D
Income Well below average
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D
Education Well below average
Source: Map AI Methodology
Population
| Metric | Decatur | Illinois Avg | U.S. Average |
|---|---|---|---|
| Population | 57,377 | 12,692,444 | 337,468,954 |
| Population density (per sq mi) | 1185.4 | 219.1 | 86.4 |
| Population growth (%/yr) | -0.95% | -0.16% | 0.59% |
| Median age | 36.3 | 37.4 | 37.3 |
| Households | 25,182 | 5,035,584 | 130,235,071 |
Population in Decatur declined by 10.4% from 2009 to 2024, reaching 57,377 in 2024.
Population Growth 2009–2024
Race & Ethnicity
Age & Sex
The largest generation in Decatur is Gen Z, aged 13–28, at 22.5% of residents. That is 1.3 points above Illinois as a whole.
- Gen Z 13–28 12,917 22.5% +1.3 pts
- Millennials 29–44 10,788 18.8% -3.1 pts
- Gen X 45–60 11,393 19.9% -0.5 pts
- Boomers 61–79 10,160 17.7% +0.8 pts
Residents by birth cohort, from the 2025 age distribution. The right-hand figure is how far each cohort's share sits above or below Illinois, in percentage points. Children younger than Gen Z and the generations before the Boomers are counted in the population but not shown here, so these shares do not add up to 100%.
Male and female share
Women are 52.7% of the people living in Decatur and men 47.3%.
- Women 52.7% Illinois 50.6%
- Men 47.3% Illinois 49.4%
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Economy
Decatur has a the economy index of D, which means it is barely prosperous.
| Metric | Decatur | Illinois Avg | U.S. Average |
|---|---|---|---|
| Median household income | $49,776 | $84,042 | $80,455 |
| Income growth (%/yr) | 3.12% | 4.46% | 4.80% |
| Unemployment rate | 8.7% | 5.8% | 5.2% |
The median household income in Decatur is about 41% lower than in Illinois.
Housing
| Metric | Decatur | Illinois Avg | U.S. Average |
|---|---|---|---|
| Median home price | $57,355 | $149,936 | $248,835 |
| Median rent | $836 | $1,274 | $1,407 |
| Homeownership rate | 60.6% | 67.1% | 65.2% |
The median home price in Decatur is about 5.7 years' worth of rent — buying at the median price costs roughly as much as paying the median rent of $836 per month for that long.
Commute Time & Mobility
Commuters in Decatur spend about 31 minutes on the road round trip each working day. Over a typical 250-day work year, that adds up to roughly 129 hours, about 5.4 full days, spent commuting.
| Metric | Decatur | Illinois Avg | U.S. Average |
|---|---|---|---|
| One-way commute (min) | 15.5 | 23.6 | 22.4 |
| Round-trip commute (min) | 31.0 | 47.3 | 44.8 |
| Yearly time spent (hours) | 129 | 197 | 187 |
| Estimated yearly cost | $4,004 | $6,104 | $5,790 |
| Work from home | 8.3% | 15.9% | 15.0% |
| Highway traffic (vehicles/day) | 3,972 | 7,977 | 8,813 |
| Local road traffic (vehicles/day) | 1,542 | 1,547 | 1,355 |
The average commute time in Decatur is 16 minutes, shorter than the 24 minutes in Illinois.
Estimated yearly cost applies a single national wage rule of thumb (U.S. Bureau of Labor Statistics average hourly earnings), not a measurement of wages in this area. Traffic volume figures come from proprietary Ticon and TrafficZoom data.
Education & Households
Decatur has a education index of D, which means it is barely educated.
| Metric | Decatur | Illinois Avg | U.S. Average |
|---|---|---|---|
| Bachelor's degree or higher | 18.5% | 34.1% | 31.6% |
| Average household size | 2.18 | 2.46 | 2.53 |
Health
Decatur has a health index of C, which means it is somewhat healthy.
| Metric | Decatur | Illinois Avg | U.S. Average |
|---|---|---|---|
| Life expectancy (years) | 74.8 | 77.9 | 78.3 |
| Self-rated poor health | 20.7% | 15.6% | 16.3% |
| Smokers | 23.3% | 19.2% | 19.0% |
Frequently Asked Questions
Common questions about Decatur, Illinois.
What is the population of Decatur, Illinois?
About 57,377 people live in Decatur, Illinois, in 25,182 households of 2.2 people on average. The median age is 36.3, close to the U.S. median of 37.3.
How densely populated is Decatur, Illinois?
Averaged over its land area, Decatur, Illinois has 1,185 people per square mile, a density typical of urban and suburban areas. That is about 14 times the U.S. average of 86.
How affordable is housing in Decatur, Illinois?
The median home costs 1.2 times the median household income ($57,355 against $49,776), compared with 3.1 times nationally. That is within the traditional rule of thumb of about 3 times income. Median rent of $836 a month takes about 20% of the median household's income, below the 30% level at which HUD considers renters cost-burdened.
Is unemployment high in Decatur, Illinois?
Unemployment in Decatur, Illinois is 8.7%, well above the U.S. rate of 5.2%, so job seekers may face more competition than elsewhere.
How educated are people in Decatur, Illinois?
18.5% of adults in Decatur, Illinois hold a bachelor's degree or higher (about 1 in 5), well below the U.S. share of 31.6%.
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