County outline
Where Jackson County is located
Area breakdown
Land accounts for 97% of Jackson County’s measured area and water for 3%. Its combined area converts to 1,873.8 square kilometers or approximately 463,036 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 701.905 | 1,817.926 | 449,219.2 |
| Water | 21.588 | 55.913 | 13,816.3 |
| Total | 723.493 | 1,873.838 | 463,035.5 |
How Jackson County compares
By original Census land area, Jackson County ranks #29 of 83 in Michigan and #1322 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.236 times the Michigan county-equivalent median of 567.8 square miles. It accounts for 1.2% of the combined county land area in the state.
See the complete Michigan ranking · What counts as a county equivalent?
Population and density of Jackson County
The Census Bureau estimates that 159,552 people lived in Jackson County on July 1, 2025. That ranks #444 of 3,222 county equivalents nationally and #14 of 83 in Michigan. Since the April 1, 2020 estimates base of 160,359, the population has declined by 807 (−0.5%), compared with +0.5% for Michigan as a whole.
With 701.9 square miles of land, that is 227 people per square mile (88 per km²), placing Jackson County #602 nationally for density and #16 in Michigan. The median county equivalent has 47 people per square mile; the Michigan median is 62. Put another way, there are about 2.8 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 160,215 | 160,195 | 159,780 | 159,607 | 159,588 | 159,552 |
| Change | — | −20 | −415 | −173 | −19 | −36 |
U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.
Cities and towns in Jackson County
Jackson County is divided into 20 municipalities and townships. In Michigan, county subdivisions are local governments, and together they cover all of the county’s land and residents.
The most populous is Jackson city, with 31,022 residents (19.4% of the county). The largest by land is Leoni township, at 48.6 mi², or 6.9% of the county’s land. Among those with at least 1,000 residents in 2020, Grass Lake charter township grew fastest since then (+3.3%).
| County subdivision | Population 2025 | Since 2020 | Land mi² | Share of county land |
|---|---|---|---|---|
| Jackson cityCounty seat | 31,022 | −0.9% | 10.8 | 1.5% |
| Blackman charter township | 24,987 | −2.5% | 31.7 | 4.5% |
| Summit township | 22,705 | −0.9% | 29.2 | 4.2% |
| Leoni township | 13,764 | −0.6% | 48.6 | 6.9% |
| Spring Arbor township | 8,526 | −0.2% | 35.1 | 5% |
| Columbia township | 7,515 | +1.8% | 36.6 | 5.2% |
| Napoleon township | 6,706 | −1.2% | 29 | 4.1% |
| Grass Lake charter township | 6,273 | +3.3% | 46.5 | 6.6% |
| Rives township | 4,794 | +0.7% | 35.8 | 5.1% |
| Henrietta township | 4,729 | +1.1% | 36 | 5.1% |
| Sandstone township | 3,873 | −1.5% | 36 | 5.1% |
| Hanover township | 3,708 | +1.4% | 34.8 | 5% |
| Liberty township | 3,080 | +0.9% | 34.3 | 4.9% |
| Waterloo township | 2,995 | +2.3% | 47.6 | 6.8% |
| Norvell township | 2,822 | +0.5% | 29.5 | 4.2% |
Show the other 5 subdivisions
| Name | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Concord township | 2,721 | +0.6% | 35.7 |
| Parma township | 2,670 | −1.1% | 36.3 |
| Tompkins township | 2,641 | +1.1% | 36 |
| Springport township | 2,142 | −0.6% | 36.1 |
| Pulaski township | 1,879 | −0.4% | 36.2 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Jackson County. Land: 2026 Census Gazetteer. How communities are listed.
Metropolitan area
Jackson County is a central county of the Jackson, MI Metropolitan Statistical Area. Jackson County is the area’s only county equivalent, so the metro area has the same 701.9 square miles of land. By combined land it ranks #321 of 393 metropolitan areas, and #278 by population.
ZIP codes
29 ZIP Code Tabulation Areas have land in Jackson County; 18 of them have most of their land inside the county, and the others mainly cover neighboring areas.
4815848827492014920249203492244923049233492344923749240492414924549246492494925049251492524925449259492614926349264492694927249277492834928449285
ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.
Counties bordering Jackson County
Jackson County shares a land border with 7 county equivalents. It has more land than 4 of them. The largest neighbor is Lenawee County (749.7 mi²) and the smallest is Ingham County (556.1 mi²). Together with its neighbors, Jackson County forms a block of 5,158.6 mi² of land, of which it holds 13.6%.
| Bordering county equivalent | Land mi² | Size vs. Jackson | Compare |
|---|---|---|---|
| Lenawee County | 749.7 | 1.1× larger | Compare |
| Calhoun County | 706.3 | about the same | Compare |
| Washtenaw County | 706 | about the same | Compare |
| Hillsdale County | 598.2 | 1.2× smaller | Compare |
| Eaton County | 575.2 | 1.2× smaller | Compare |
| Livingston County | 565.3 | 1.2× smaller | Compare |
| Ingham County | 556.1 | 1.3× smaller | Compare |
How big is Jackson County compared with U.S. states?
Jackson County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.5 times as much. Michigan’s county land could hold about 81 areas the size of Jackson County.
Another way to picture it: the same land area would fill a square about 26.5 miles (42.6 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.
State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.
What stands out about Jackson County?
Jackson County has more land than 1,900 of the other 3,221 county equivalents in the dataset.
A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.
Does including water change its rank?
Using land plus water places Jackson County at #1,344 nationally by total area, 22 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.
Its water share is 3%, compared with a national county-equivalent median of 1.2% — 1.8 percentage points higher. This describes the statistical geography’s land/water mix, not flood exposure or developable land.
Closest positions in the national land ranking
These entries sit immediately beside Jackson County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #1321 | Ashtabula County, Ohio | 702.4 | Compare |
| #1322 | Jackson County, Michigan | 701.9 | This county |
| #1323 | Mitchell County, Kansas | 701.8 | Compare |
Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.
Representative coordinates
The Census internal point is 42.248474, -84.420868. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.
Source and precision
U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 1,817,926,228 m²; AWATER: 55,912,049 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.
Common questions
How big is Jackson County?
Jackson County, Michigan has 701.9 square miles (1,817.9 km²) of land and 21.6 square miles of water, for a total area of 723.5 square miles. It ranks #1322 of 3,222 U.S. county equivalents by land area.
Is Jackson County the largest county in Michigan?
No. Jackson County ranks #29 of 83 in Michigan by land area. The largest is Marquette County, with 1,809.1 square miles of land.
What counties border Jackson County?
Jackson County shares a land border with Washtenaw County, Calhoun County, Ingham County, Hillsdale County, Lenawee County, Eaton County, and Livingston County.
What is the population of Jackson County?
The Census Bureau estimates Jackson County had 159,552 residents on July 1, 2025, ranking #444 of 3,222 county equivalents. That is 227 people per square mile of land.
What is the county seat of Jackson County?
The county seat of Jackson County is Jackson.
What cities and towns are in Jackson County?
Jackson County has 20 county subdivisions (cities, towns and townships). The most populous five are Jackson city, Blackman charter township, Summit township, Leoni township, and Spring Arbor township.
Is Jackson County part of a metropolitan area?
Yes. It is a central county of the Jackson, MI Metropolitan Statistical Area.
How many ZIP codes are in Jackson County?
29 ZIP Code Tabulation Areas have land in Jackson County, and 18 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Jackson County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1.5 times as much land.
How many acres of land are in Jackson County?
The land measurement converts to approximately 449,219 acres. Including water, total area is approximately 463,036 acres. One square mile equals 640 acres.
Why might another source show a different area?
Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.
Can this establish a property boundary?
No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.