Cumberland County area

Cumberland County, Pennsylvania covers 550.4 square miles: 545.5 square miles of land and 4.89 square miles of water. Its county seat is Carlisle. An estimated 277,270 people lived there in 2025.

Official Census measurements · GEOID 420412026 Gazetteer · retrieved September 27, 2026
Land area545.5 mi²
Water area4.89 mi²
Population (2025)277,270
People per mi²508

County outline

Generalized outline of Cumberland County, Pennsylvania
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 Cumberland County is located

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

Area breakdown

Land accounts for 99.1% of Cumberland County’s measured area and water for 0.9%. Its combined area converts to 1,425.5 square kilometers or approximately 352,239 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land545.4831,412.794349,109.1
Water4.8912.6653,129.6
Total550.3731,425.46352,238.7

How Cumberland County compares

By original Census land area, Cumberland County ranks #41 of 67 in Pennsylvania and #1911 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 0.835 times the Pennsylvania county-equivalent median of 653.3 square miles. It accounts for 1.2% of the combined county land area in the state.

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

Population and density of Cumberland County

The Census Bureau estimates that 277,270 people lived in Cumberland County on July 1, 2025. That ranks #268 of 3,222 county equivalents nationally and #15 of 67 in Pennsylvania. Since the April 1, 2020 estimates base of 259,461, the population has grown by 17,809 (+6.9%), compared with +0.4% for Pennsylvania as a whole.

With 545.5 square miles of land, that is 508 people per square mile (196 per km²), placing Cumberland County #336 nationally for density and #13 in Pennsylvania. The median county equivalent has 47 people per square mile; the Pennsylvania median is 137. Put another way, there are about 1.3 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate260,251265,577268,588271,177274,656277,270
Change—+5,326+3,011+2,589+3,479+2,614

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 Cumberland County

Cumberland County is divided into 33 municipalities and townships. In Pennsylvania, county subdivisions are local governments, and together they cover all of the county’s land and residents.

The most populous is Hampden township, with 35,401 residents (12.8% of the county). The largest by land is Southampton township, at 51.4 mi², or 9.4% of the county’s land. The county seat, Carlisle borough, has 22,693 residents. Among those with at least 1,000 residents in 2020, Southampton township grew fastest since then (+14.5%).

County subdivisionPopulation 2025Since 2020Land mi²Share of county land
Hampden township35,401+8.1%17.33.2%
Upper Allen township24,700+6.2%13.22.4%
Carlisle boroughCounty seat22,693+12.8%5.5331%
Silver Spring township21,670+11%32.35.9%
East Pennsboro township21,658+3.6%10.51.9%
Lower Allen township21,254+5.9%10.11.8%
South Middleton township17,792+10.2%48.88.9%
North Middleton township13,031+7.8%23.24.3%
Mechanicsburg borough10,037+8.3%2.410.4%
Southampton township8,523+14.5%51.49.4%
Camp Hill borough8,199+1%2.1250.4%
Middlesex township7,636+9.7%25.74.7%
New Cumberland borough7,590+0.8%1.6750.3%
Monroe township6,748+8.5%26.14.8%
West Pennsboro township5,699+2%30.25.5%
Show the other 18 subdivisions
NamePopulation 2025Since 2020Land mi²
Dickinson township5,519+4.1%45.8
Lemoyne borough4,801+2.6%1.612
Shippensburg borough4,434+2.9%1.311
Shippensburg township4,343+0.9%2.481
Wormleysburg borough3,078+1.2%0.777
Penn township2,937+2.3%29.6
North Newton township2,600+2.1%22.8
Hopewell township2,559+3%27.7
Upper Frankford township2,309+8.3%19.4
Mount Holly Springs borough2,019+1.3%1.36
Lower Frankford township1,833+4.8%14.7
Lower Mifflin township1,795+2.3%23.8
Shiremanstown borough1,657+0.9%0.306
Newville borough1,409+1.1%0.419
South Newton township1,393+1.5%11.3
Upper Mifflin township1,381+4.1%21.7
Newburg borough359+1.7%0.185
Cooke township213+2.4%19.8

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Cumberland County. Land: 2026 Census Gazetteer. How communities are listed.

Metropolitan area

Cumberland County is a central county of the Harrisburg-Carlisle, PA Metropolitan Statistical Area. Its 3 county equivalents have 617,427 residents on 1,621.8 square miles of land; Cumberland County accounts for 33.6% of the land and 44.9% of the residents. By combined land it ranks #200 of 393 metropolitan areas, and #96 by population. It belongs to the Harrisburg-York-Lebanon, PA Combined Statistical Area.

County equivalentPopulation 2025Land mi²
Dauphin County293,351524.9
Cumberland County277,270545.5
Perry County46,806551.5

ZIP codes

21 ZIP Code Tabulation Areas have land in Cumberland County; 17 of them have most of their land inside the county, and the others mainly cover neighboring areas.

170071701117013170151701917025170271704317050170531705517065170701708117093172401724117257172661730717324

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 Cumberland County

Cumberland County shares a land border with 5 county equivalents. It has more land than 2 of them. The largest neighbor is York County (904.4 mi²) and the smallest is Adams County (518.6 mi²). Together with its neighbors, Cumberland County forms a block of 3,817 mi² of land, of which it holds 14.3%.

Map of Cumberland County and the 5 county equivalents that border it Perry County, Pennsylvania: 551.5 mi² landAdams County, Pennsylvania: 518.6 mi² landFranklin County, Pennsylvania: 772.3 mi² landYork County, Pennsylvania: 904.4 mi² landDauphin County, Pennsylvania: 524.9 mi² land
Cumberland 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. CumberlandCompare
York County904.41.7× largerCompare
Franklin County772.31.4× largerCompare
Perry County551.5about the sameCompare
Dauphin County524.9about the sameCompare
Adams County518.61.1× smallerCompare

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

Cumberland 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. Pennsylvania’s county land could hold about 82 areas the size of Cumberland County.

Land area: Cumberland County and the closest-sized states
Cumberland County545.5 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 23.4 miles (37.6 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 Cumberland County?

Cumberland County has more land than 1,311 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Cumberland County545.5 mi²
Pennsylvania median653.3 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 Cumberland County at #2,005 nationally by total area, 94 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 0.9%, compared with a national county-equivalent median of 1.2% — 0.3 percentage points lower. 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 Cumberland County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#1910Hall County, Nebraska546.5Compare
#1911Cumberland County, Pennsylvania545.5This county
#1912Franklin County, Florida545Compare

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 40.164805, -77.263442. 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: 1,412,794,386 m²; AWATER: 12,664,175 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 Cumberland County?

Cumberland County, Pennsylvania has 545.5 square miles (1,412.8 km²) of land and 4.89 square miles of water, for a total area of 550.4 square miles. It ranks #1911 of 3,222 U.S. county equivalents by land area.

Is Cumberland County the largest county in Pennsylvania?

No. Cumberland County ranks #41 of 67 in Pennsylvania by land area. The largest is Lycoming County, with 1,228.9 square miles of land.

What counties border Cumberland County?

Cumberland County shares a land border with Perry County, Adams County, Franklin County, York County, and Dauphin County.

What is the population of Cumberland County?

The Census Bureau estimates Cumberland County had 277,270 residents on July 1, 2025, ranking #268 of 3,222 county equivalents. That is 508 people per square mile of land.

What is the county seat of Cumberland County?

The county seat of Cumberland County is Carlisle.

What cities and towns are in Cumberland County?

Cumberland County has 33 county subdivisions (cities, towns and townships). The most populous five are Hampden township, Upper Allen township, Carlisle borough, Silver Spring township, and East Pennsboro township.

Is Cumberland County part of a metropolitan area?

Yes. It is a central county of the Harrisburg-Carlisle, PA Metropolitan Statistical Area, which has 3 county equivalents and 617,427 residents.

How many ZIP codes are in Cumberland County?

21 ZIP Code Tabulation Areas have land in Cumberland County, and 17 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

How does Cumberland 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 Cumberland County?

The land measurement converts to approximately 349,109 acres. Including water, total area is approximately 352,239 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