Franklin County area

Franklin County, Indiana covers 391 square miles: 384.4 square miles of land and 6.623 square miles of water. Its county seat is Brookville. An estimated 23,286 people lived there in 2025.

Official Census measurements · GEOID 180472026 Gazetteer · retrieved September 27, 2026
Land area384.4 mi²
Water area6.623 mi²
Population (2025)23,286
People per mi²61

County outline

Generalized outline of Franklin County, Indiana
2025 Census cartographic boundary, fitted to this frame. County maps are not at a common scale. The 2026 area measurements below come from the separate Gazetteer release. Map source and limitations.

Where Franklin County is located

Franklin County highlighted on a map of all U.S. county equivalents. About the maps

Area breakdown

Land accounts for 98.3% of Franklin County’s measured area and water for 1.7%. Its combined area converts to 1,012.8 square kilometers or approximately 250,271 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land384.426995.659246,032.6
Water6.62317.1534,238.7
Total391.0491,012.812250,271.4

How Franklin County compares

By original Census land area, Franklin County ranks #55 of 92 in Indiana and #2589 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 0.97 times the Indiana county-equivalent median of 396.4 square miles. It accounts for 1.1% of the combined county land area in the state.

See the complete Indiana ranking · What counts as a county equivalent?

Population and density of Franklin County

The Census Bureau estimates that 23,286 people lived in Franklin County on July 1, 2025. That ranks #1,726 of 3,222 county equivalents nationally and #67 of 92 in Indiana. Since the April 1, 2020 estimates base of 22,790, the population has grown by 496 (+2.2%), compared with +2.8% for Indiana as a whole.

With 384.4 square miles of land, that is 61 people per square mile (23 per km²), placing Franklin County #1,378 nationally for density and #64 in Indiana. The median county equivalent has 47 people per square mile; the Indiana median is 88. Put another way, there are about 11 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate22,79122,88723,10423,18423,13623,286
Change—+96+217+80−48+150

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 Franklin County

6 incorporated places lie at least partly in Franklin County. Together they are home to 5,973 people (25.7%); the other 17,313 (74.3%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Brookville town, with 2,663 residents in the county. By land, Batesville city is the largest at 6.154 mi² across all its counties. Among places with at least 1,000 residents in 2020, Batesville city grew fastest since then (+3.9%).

Incorporated placePopulation 2025Since 2020Land mi²
Brookville townCounty seat2,663+1.7%1.397
Batesville cityAlso in 1 other county2,007+3.9%6.154
Oldenburg town651+1.1%0.43
Laurel town414+1.2%0.238
Cedar Grove town148+0.7%0.151
Mount Carmel town90+3.4%0.044

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Franklin County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Franklin County is an outlying county of the Cincinnati, OH-KY-IN Metropolitan Statistical Area. Its 15 county equivalents have 2,312,858 residents on 4,385.2 square miles of land; Franklin County accounts for 8.8% of the land and 1% of the residents. By combined land it ranks #60 of 393 metropolitan areas, and #30 by population. It belongs to the Cincinnati-Wilmington, OH-KY-IN Combined Statistical Area.

County equivalentPopulation 2025Land mi²
Hamilton CountyOhio838,418405.5
Butler CountyOhio400,128466.5
Warren CountyOhio257,181401.4
Clermont CountyOhio216,977452.6
Kenton CountyKentucky175,779160.4
Boone CountyKentucky145,316246.3
Campbell CountyKentucky95,441151.3
Dearborn County51,609305.1
Brown CountyOhio44,397489.6
Grant CountyKentucky26,181258
Franklin County23,286384.4
Pendleton CountyKentucky14,800277.1
Gallatin CountyKentucky8,84098.3
Bracken CountyKentucky8,511202.7
Ohio County5,99486.2

ZIP codes

15 ZIP Code Tabulation Areas have land in Franklin County; 7 of them have most of their land inside the county, and the others mainly cover neighboring areas.

461734700347006470104701247016470244703047035470364704147060472404733147353

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 Franklin County

Franklin County shares a land border with 7 county equivalents, including 1 in Ohio. It has more land than 4 of them. The largest neighbor is Butler County (466.5 mi²) and the smallest is Union County (161.2 mi²). Together with its neighbors, Franklin County forms a block of 2,759.4 mi² of land, of which it holds 13.9%.

Map of Franklin County and the 7 county equivalents that border it Butler County, Ohio: 466.5 mi² landFayette County, Indiana: 215 mi² landDearborn County, Indiana: 305.1 mi² landDecatur County, Indiana: 372.6 mi² landRipley County, Indiana: 446.4 mi² landUnion County, Indiana: 161.2 mi² landRush County, Indiana: 408.1 mi² land
Franklin County (dark) and its bordering county equivalents. Select a neighbor to open its profile. Drawn from the 2025 Census cartographic boundaries in an equal-area projection. How borders are determined.
Bordering county equivalentLand mi²Size vs. FranklinCompare
Butler CountyOhio466.51.2× largerCompare
Ripley County446.41.2× largerCompare
Rush County408.11.1× largerCompare
Decatur County372.6about the sameCompare
Dearborn County305.11.3× smallerCompare
Fayette County2151.8× smallerCompare
Union County161.22.4× smallerCompare

How big is Franklin County compared with U.S. states?

Franklin County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.7 times as much. Indiana’s county land could hold about 93 areas the size of Franklin County.

Land area: Franklin County and the closest-sized states
Franklin County384.4 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 19.6 miles (31.6 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 Franklin County?

Franklin County has more land than 633 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Franklin County384.4 mi²
Indiana median396.4 mi²
National median604.5 mi²

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 Franklin County at #2,634 nationally by total area, 45 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 1.7%, compared with a national county-equivalent median of 1.2% — 0.5 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 Franklin County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#2588Warrick County, Indiana384.6Compare
#2589Franklin County, Indiana384.4This county
#2590Jay County, Indiana383.9Compare

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 39.409762, -85.066964. 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: 995,659,501 m²; AWATER: 17,154,640 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.

Download the official county source ZIP ↗ · Methodology

Common questions

How big is Franklin County?

Franklin County, Indiana has 384.4 square miles (995.7 km²) of land and 6.623 square miles of water, for a total area of 391 square miles. It ranks #2589 of 3,222 U.S. county equivalents by land area.

Is Franklin County the largest county in Indiana?

No. Franklin County ranks #55 of 92 in Indiana by land area. The largest is Allen County, with 657.1 square miles of land.

What counties border Franklin County?

Franklin County shares a land border with Butler County, Ohio, Fayette County, Dearborn County, Decatur County, Ripley County, Union County, and Rush County.

What is the population of Franklin County?

The Census Bureau estimates Franklin County had 23,286 residents on July 1, 2025, ranking #1,726 of 3,222 county equivalents. That is 61 people per square mile of land.

What is the county seat of Franklin County?

The county seat of Franklin County is Brookville.

What cities and towns are in Franklin County?

Franklin County has 6 incorporated places. The most populous five are Brookville town, Batesville city, Oldenburg town, Laurel town, and Cedar Grove town; 17,313 residents live outside any incorporated place.

Is Franklin County part of a metropolitan area?

Yes. It is an outlying county of the Cincinnati, OH-KY-IN Metropolitan Statistical Area, which has 15 county equivalents and 2,312,858 residents.

How many ZIP codes are in Franklin County?

15 ZIP Code Tabulation Areas have land in Franklin County, and 7 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

How does Franklin County compare with U.S. states?

It has less land than every state. Rhode Island, the smallest, has 2.7 times as much land.

How many acres of land are in Franklin County?

The land measurement converts to approximately 246,033 acres. Including water, total area is approximately 250,271 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.

Cite this county

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