Franklin County area

Franklin County, Ohio covers 543.6 square miles: 532.4 square miles of land and 11.2 square miles of water. Its county seat is Columbus. An estimated 1,361,536 people lived there in 2025.

Official Census measurements · GEOID 390492026 Gazetteer · retrieved September 27, 2026
Land area532.4 mi²
Water area11.2 mi²
Population (2025)1,361,536
People per mi²2,557

County outline

Generalized outline of Franklin County, Ohio
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 97.9% of Franklin County’s measured area and water for 2.1%. Its combined area converts to 1,408 square kilometers or approximately 347,917 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land532.4321,378.993340,756.5
Water11.18928.9797,161
Total543.6211,407.972347,917.4

How Franklin County compares

By original Census land area, Franklin County ranks #17 of 88 in Ohio and #1960 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 1.221 times the Ohio county-equivalent median of 436 square miles. It accounts for 1.3% of the combined county land area in the state.

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

Population and density of Franklin County

The Census Bureau estimates that 1,361,536 people lived in Franklin County on July 1, 2025. That ranks #32 of 3,222 county equivalents nationally and #1 of 88 in Ohio. Since the April 1, 2020 estimates base of 1,323,793, the population has grown by 37,743 (+2.9%), compared with +0.9% for Ohio as a whole.

With 532.4 square miles of land, that is 2,557 people per square mile (987 per km²), placing Franklin County #57 nationally for density and #2 in Ohio. The median county equivalent has 47 people per square mile; the Ohio median is 120. Put another way, there are about 0.25 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate1,324,4781,317,2281,326,3921,337,0951,352,6561,361,536
Change—−7,250+9,164+10,703+15,561+8,880

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

27 incorporated places lie at least partly in Franklin County. Together they are home to 1,262,158 people (92.7%); the other 99,378 (7.3%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Columbus city, with 911,199 residents in the county (the city extends into 2 other counties). Among places with at least 1,000 residents in 2020, Obetz city grew fastest since then (+33.9%).

Incorporated placePopulation 2025Since 2020Land mi²
Columbus cityCounty seat · Also in 2 other counties911,199+3.5%222.9
Grove City city45,180+9.5%19
Dublin cityAlso in 2 other counties40,613−0.3%25.1
Hilliard city38,898+4.7%14.2
Gahanna city35,986+0.7%12.4
Upper Arlington city35,893−2.4%9.807
Reynoldsburg cityAlso in 2 other counties31,016+4.3%11.3
Westerville cityAlso in 1 other county29,046−3.1%12.6
Whitehall city19,805−1.6%5.286
Worthington city14,543−1.6%5.473
Bexley city12,452−10.6%2.421
New Albany cityAlso in 1 other county11,399+5.6%21.9
Grandview Heights city9,112+12.7%1.316
Canal Winchester cityAlso in 1 other county8,250+11.3%8.297
Obetz city7,342+33.9%5.825
Show the other 12 places
NamePopulation 2025Since 2020Land mi²
Groveport city5,818−3.2%8.786
Minerva Park village1,950−3.1%0.647
Urbancrest village1,003−3.1%0.587
Marble Cliff village658+3.1%0.281
Valleyview village640−2.9%0.143
Riverlea village578−3.2%0.151
Harrisburg villageAlso in 1 other county313−0.3%0.155
Lockbourne villageAlso in 1 other county228−3.8%0.797
Brice village110+17%0.088
Pickerington cityAlso in 1 other county77+10%10.4
Lithopolis villageAlso in 1 other county49−2%2.269
Commercial Point villageAlso in 1 other county0—4.687

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 a central county of the Columbus, OH Metropolitan Statistical Area. Its 10 county equivalents have 2,242,028 residents on 4,797.5 square miles of land; Franklin County accounts for 11.1% of the land and 60.7% of the residents. By combined land it ranks #55 of 393 metropolitan areas, and #32 by population. It belongs to the Columbus-Marion-Zanesville, OH Combined Statistical Area.

County equivalentPopulation 2025Land mi²
Franklin County1,361,536532.4
Delaware County242,032443.1
Licking County185,564682.4
Fairfield County169,752504.4
Union County73,446431.7
Pickaway County62,978501.3
Madison County46,985466.7
Morrow County36,305406.1
Perry County35,918407.9
Hocking County27,512421.4

ZIP codes

50 ZIP Code Tabulation Areas have land in Franklin County; 42 of them have most of their land inside the county, and the others mainly cover neighboring areas.

4300243004430164301743026430544306443065430684308143085431094311043119431234312543126431374314043146431474320143202432034320443205432064320743209432104321143212432134321443215432174321843219432204322143222432234322443227432284322943230432314323243235

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 6 county equivalents. It has more land than 5 of them. The largest neighbor is Licking County (682.4 mi²) and the smallest is Union County (431.7 mi²). Together with its neighbors, Franklin County forms a block of 3,562 mi² of land, of which it holds 14.9%.

Map of Franklin County and the 6 county equivalents that border it Pickaway County, Ohio: 501.3 mi² landDelaware County, Ohio: 443.1 mi² landMadison County, Ohio: 466.7 mi² landLicking County, Ohio: 682.4 mi² landFairfield County, Ohio: 504.4 mi² landUnion County, Ohio: 431.7 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
Licking County682.41.3× largerCompare
Fairfield County504.41.1× smallerCompare
Pickaway County501.31.1× smallerCompare
Madison County466.71.1× smallerCompare
Delaware County443.11.2× smallerCompare
Union County431.71.2× 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 1.9 times as much. Ohio’s county land could hold about 77 areas the size of Franklin County.

Land area: Franklin County and the closest-sized states
Franklin County532.4 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 23.1 miles (37.1 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 1,262 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Franklin County532.4 mi²
Ohio median436 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 #2,026 nationally by total area, 66 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 2.1%, compared with a national county-equivalent median of 1.2% — 0.9 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
#1959Jefferson County, Kansas532.6Compare
#1960Franklin County, Ohio532.4This county
#1961Livingston County, Missouri532.3Compare

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 39.969875, -83.009086. 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: 1,378,992,893 m²; AWATER: 28,978,544 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, Ohio has 532.4 square miles (1,379 km²) of land and 11.2 square miles of water, for a total area of 543.6 square miles. It ranks #1960 of 3,222 U.S. county equivalents by land area.

Is Franklin County the largest county in Ohio?

No. Franklin County ranks #17 of 88 in Ohio by land area. The largest is Ashtabula County, with 702.4 square miles of land.

What counties border Franklin County?

Franklin County shares a land border with Pickaway County, Delaware County, Madison County, Licking County, Fairfield County, and Union County.

What is the population of Franklin County?

The Census Bureau estimates Franklin County had 1,361,536 residents on July 1, 2025, ranking #32 of 3,222 county equivalents. That is 2,557 people per square mile of land.

What is the county seat of Franklin County?

The county seat of Franklin County is Columbus.

What cities and towns are in Franklin County?

Franklin County has 27 incorporated places. The most populous five are Columbus city, Grove City city, Dublin city, Hilliard city, and Gahanna city; 99,378 residents live outside any incorporated place.

Is Franklin County part of a metropolitan area?

Yes. It is a central county of the Columbus, OH Metropolitan Statistical Area, which has 10 county equivalents and 2,242,028 residents.

How many ZIP codes are in Franklin County?

50 ZIP Code Tabulation Areas have land in Franklin County, and 42 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 1.9 times as much land.

How many acres of land are in Franklin County?

The land measurement converts to approximately 340,756 acres. Including water, total area is approximately 347,917 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

Download the complete CSV or JSON dataset