Marble Rock, Iowa Demographics & Population 2026
During the 2020–2024 ACS period, Marble Rock, Iowa had a total population of 191, the 705th largest city in Iowa, with a median household income of $65,625, which is 13% lower than the state average. The poverty rate is 6.3%.
Data vintage: U.S. Census Bureau ACS 2020–2024 5-Year Estimates · refreshed July 2026 · Methodology & source notes
Key Takeaways
- Only 3.8% of adults have a bachelor's degree, well below the national average of 35.7%.
- Housing is very affordable with a home-value-to-income ratio of just 1.2x.
Marble Rock Quick Facts
How Marble Rock Changed
Change from the 2019–2023 ACS period to 2020–2024. These are rolling five-year estimates, not year-over-year measurements.
| Metric | 2019–2023 | 2020–2024 | Change |
|---|---|---|---|
| Population | 199 | 191 | -4.0% |
| Median household income | $65,938 | $65,625 | -0.5% |
| Median home value | $59,300 | $76,000 | +28.2% |
How Marble Rock Compares
Median Household Income
Median Home Value
Economy & Housing
Household Income Distribution
Detailed income brackets
Employment
Housing Overview
People & Demographics
Age Distribution
Race & Ethnicity
Diversity Index
A less diverse community where one racial or ethnic group represents a large majority.
State average: 31 | National average: 61
Education
Educational Attainment (Adults 25+)
Marble Rock Rankings in Iowa
Explore Iowa Rankings
Other Cities in Floyd County
| City | Population | Median Income | Poverty | Home Value |
|---|---|---|---|---|
| Charles City | 7,232 | $59,180 | 13.3% | $115,400 |
| Nashua | 1,622 | $66,597 | 7.3% | $129,600 |
| Greene | 1,339 | $56,335 | 17.3% | $120,700 |
| Rockford | 839 | $65,428 | 10.8% | $94,600 |
| Rudd | 481 | $75,833 | 12.7% | $111,600 |
| Floyd | 315 | $63,393 | 6.3% | $107,700 |
| Colwell | 38 | N/A | 0.0% | $101,400 |
| Roseville | 12 | N/A | 0.0% | N/A |
Cities Similar to Marble Rock
These cities in the same state have comparable population and economic profiles.
| City | Population | Median Income | Home Value | Bachelor's+ | Poverty |
|---|---|---|---|---|---|
| Weston | 192 | N/A | N/A | 65.5% | 0.0% |
| Bentley | 189 | N/A | $188,900 | 63.7% | 6.3% |
| Dixon | 190 | $62,500 | $121,500 | 10.4% | 4.2% |
| Rippey | 196 | $65,000 | $56,800 | 4.9% | 21.4% |
| Conroy | 199 | N/A | $213,000 | 51.8% | 4.0% |
A note before these figures: with a population of 191, Marble Rock's ACS estimates come from a small number of survey responses and carry wide margins of error. Individual percentages below — particularly rates that round to 0% or 100% — are approximations, not precise measurements. See data.census.gov for the published margins of error.
Population Overview
Marble Rock is a small community located in Iowa, within Floyd County. The total population is 191. It ranks as the 705th most populous out of 1,017 Census-designated places in Iowa.
Age Demographics
The median age in Marble Rock is 51.5 years. This is 33% higher than the state median of 38.6 years. 11.5% of residents are 75 or older, suggesting a significant retirement-age population with implications for healthcare services and senior housing.
Economy, Income & Housing
The median household income in Marble Rock is $65,625. This is 13% lower than the state median of $75,059. It is also 19% lower than the national median of $80,734. The poverty rate stands at 6.3%. This is 43% lower than the state poverty rate of 11.1%. The unemployment rate is 5.7%. This is 59% higher than the state rate of 3.6%. The median home value is $76,000. Housing costs are 63% lower than the state median of $208,000. With a home-value-to-income ratio of just 1.2x, Marble Rock is one of the most affordable housing markets in the area. 75.9% of occupied housing units are owner-occupied. This homeownership rate is 6% higher than the state average of 71.7%.
Race & Ethnicity
Marble Rock has a predominantly White (non-Hispanic) population, comprising 93.7% of all residents.
Education
3.8% of residents aged 25 and older hold a bachelor's degree or higher. This is among the lowest rates in the state, which may correlate with employment and income patterns. This is 88% lower than the state rate of 31.4%. Nationally, 35.7% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 95.5%.
Data Sources & Methodology
All demographic data for Marble Rock, Iowa is sourced from the U.S. Census Bureau's American Community Survey (ACS) 2020–2024 5-Year Estimates. The ACS collects data from approximately 3.5 million households annually and pools five years of responses so that even small communities can be measured, though the margin of error widens as the population falls. Comparisons are made against Iowa state averages and national averages calculated from the same dataset. Rankings reflect the city's position among all 1,017 Census-designated places in Iowa. Read more about how these figures are produced on our methodology page, or visit data.census.gov for official data.
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Frequently Asked Questions
What is the population of Marble Rock, Iowa?
Marble Rock, Iowa has a population of 191 according to the most recent U.S. Census ACS 5-Year Estimates.
What is the median household income in Marble Rock, IA?
The median household income in Marble Rock is $65,625, which is 19% lower than the national median of $80,734.
What is the poverty rate in Marble Rock, IA?
The poverty rate in Marble Rock is 6.3%. This means approximately 12 residents live below the federal poverty line.
What is the racial makeup of Marble Rock, Iowa?
Marble Rock's population is 93.7% White, 0.0% Black, 0.0% Hispanic/Latino, and 0.0% Asian.
What is the median home value in Marble Rock, IA?
The median home value in Marble Rock is $76,000. The home-value-to-income ratio is 1.2x.
How educated is Marble Rock, Iowa?
3.8% of adults (25+) in Marble Rock hold a bachelor's degree or higher, and 1.5% hold a graduate or professional degree.