Pike County area

Pike County, Illinois covers 848.8 square miles: 831.4 square miles of land and 17.5 square miles of water. Its county seat is Pittsfield. An estimated 14,231 people lived there in 2025.

Official Census measurements · GEOID 171492026 Gazetteer · retrieved September 27, 2026
Land area831.4 mi²
Water area17.5 mi²
Population (2025)14,231
People per mi²17

County outline

Generalized outline of Pike County, Illinois
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 Pike County is located

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

Area breakdown

Land accounts for 97.9% of Pike County’s measured area and water for 2.1%. Its combined area converts to 2,198.4 square kilometers or approximately 543,247 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land831.3522,153.192532,065.3
Water17.47245.25211,182.1
Total848.8242,198.444543,247.4

How Pike County compares

By original Census land area, Pike County ranks #14 of 102 in Illinois and #1014 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 1.628 times the Illinois county-equivalent median of 510.7 square miles. It accounts for 1.5% of the combined county land area in the state.

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

Population and density of Pike County

The Census Bureau estimates that 14,231 people lived in Pike County on July 1, 2025. That ranks #2,213 of 3,222 county equivalents nationally and #73 of 102 in Illinois. Since the April 1, 2020 estimates base of 14,728, the population has declined by 497 (−3.4%), compared with −0.8% for Illinois as a whole.

With 831.4 square miles of land, that is 17 people per square mile (6.6 per km²), placing Pike County #2,405 nationally for density and #97 in Illinois. The median county equivalent has 47 people per square mile; the Illinois median is 44. Put another way, there are about 37 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate14,63514,60014,53914,35114,28614,231
Change—−35−61−188−65−55

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 Pike County

17 incorporated places lie at least partly in Pike County. Together they are home to 9,451 people (66.4%); the other 4,780 (33.6%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Pittsfield city, with 4,041 residents in the county.

Incorporated placePopulation 2025Since 2020Land mi²
Pittsfield cityCounty seat4,041−3.6%4.782
Barry city1,247−4.2%1.432
Griggsville city1,047−4.7%1.106
Pleasant Hill village895−2.5%0.765
Hull village376−4.8%1.825
New Canton town325−3%0.881
Perry village302−3.8%0.386
Nebo village270−2.9%0.434
Milton village206−2.4%0.386
Kinderhook village188−2.1%0.808
Baylis village165−2.9%0.471
New Salem village116−4.1%1.049
Pearl village108−2.7%1.505
Detroit village74−1.3%0.251
El Dara village61−4.7%1.011
Show the other 2 places
NamePopulation 2025Since 2020Land mi²
Florence village17−5.6%0.276
Valley City village13+8.3%0.27

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

Metropolitan area

Pike County is not part of any metropolitan or micropolitan statistical area in the Office of Management and Budget’s July 2023 delineation; 1,306 other county equivalents are also outside one. These areas are built around an urban core of at least 10,000 people plus the counties tied to it by commuting, so counties outside them are generally rural.

ZIP codes

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

62312623146232362340623436234562352623536235562356623576236162362623636236662370

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 Pike County

Pike County shares a land border with 9 county equivalents, including 3 in Missouri. It has more land than 8 of them. The largest neighbor is Adams County (855.2 mi²) and the smallest is Scott County (250.8 mi²). Together with its neighbors, Pike County forms a block of 5,186.1 mi² of land, of which it holds 16%.

Map of Pike County and the 9 county equivalents that border it Adams County, Illinois: 855.2 mi² landScott County, Illinois: 250.8 mi² landPike County, Missouri: 670.4 mi² landBrown County, Illinois: 305.7 mi² landCalhoun County, Illinois: 253.8 mi² landGreene County, Illinois: 543.1 mi² landRalls County, Missouri: 469.8 mi² landMarion County, Missouri: 436.9 mi² landMorgan County, Illinois: 569 mi² land
Pike 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. PikeCompare
Adams County855.2about the sameCompare
Pike CountyMissouri670.41.2× smallerCompare
Morgan County5691.5× smallerCompare
Greene County543.11.5× smallerCompare
Ralls CountyMissouri469.81.8× smallerCompare
Marion CountyMissouri436.91.9× smallerCompare
Brown County305.72.7× smallerCompare
Calhoun County253.83.3× smallerCompare
Scott County250.83.3× smallerCompare

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

Pike County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.2 times as much. Illinois’s county land could hold about 67 areas the size of Pike County.

Land area: Pike County and the closest-sized states
Pike County831.4 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 28.8 miles (46.4 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 Pike County?

Pike County has more land than 2,208 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Pike County831.4 mi²
Illinois median510.7 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 Pike County at #1,090 nationally by total area, 76 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 Pike County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#1013Avoyelles Parish, Louisiana831.4Compare
#1014Pike County, Illinois831.4This county
#1015Washington County, New York831.2Compare

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 39.625106, -90.889034. 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: 2,153,190,727 m²; AWATER: 45,251,537 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 Pike County?

Pike County, Illinois has 831.4 square miles (2,153.2 km²) of land and 17.5 square miles of water, for a total area of 848.8 square miles. It ranks #1014 of 3,222 U.S. county equivalents by land area.

Is Pike County the largest county in Illinois?

No. Pike County ranks #14 of 102 in Illinois by land area. The largest is McLean County, with 1,183.2 square miles of land.

What counties border Pike County?

Pike County shares a land border with Adams County, Scott County, Pike County, Missouri, Brown County, Calhoun County, Greene County, Ralls County, Missouri, Marion County, Missouri, and Morgan County.

What is the population of Pike County?

The Census Bureau estimates Pike County had 14,231 residents on July 1, 2025, ranking #2,213 of 3,222 county equivalents. That is 17 people per square mile of land.

What is the county seat of Pike County?

The county seat of Pike County is Pittsfield.

What cities and towns are in Pike County?

Pike County has 17 incorporated places. The most populous five are Pittsfield city, Barry city, Griggsville city, Pleasant Hill village, and Hull village; 4,780 residents live outside any incorporated place.

Is Pike County part of a metropolitan area?

No. Pike County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.

How many ZIP codes are in Pike County?

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

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

It has less land than every state. Rhode Island, the smallest, has 1.2 times as much land.

How many acres of land are in Pike County?

The land measurement converts to approximately 532,065 acres. Including water, total area is approximately 543,247 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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