Miami County area

Miami County, Kansas covers 590.3 square miles: 575.9 square miles of land and 14.4 square miles of water. Its county seat is Paola. An estimated 36,240 people lived there in 2025.

Official Census measurements · GEOID 201212026 Gazetteer · retrieved September 27, 2026
Land area575.9 mi²
Water area14.4 mi²
Population (2025)36,240
People per mi²63

County outline

Generalized outline of Miami County, Kansas
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 Miami County is located

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

Area breakdown

Land accounts for 97.6% of Miami County’s measured area and water for 2.4%. Its combined area converts to 1,528.8 square kilometers or approximately 377,763 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land575.881,491.522368,563.2
Water14.37537.2319,200
Total590.2551,528.753377,763.2

How Miami County compares

By original Census land area, Miami County ranks #88 of 105 in Kansas and #1720 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 0.789 times the Kansas county-equivalent median of 729.7 square miles. It accounts for 0.7% of the combined county land area in the state.

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

Population and density of Miami County

The Census Bureau estimates that 36,240 people lived in Miami County on July 1, 2025. That ranks #1,321 of 3,222 county equivalents nationally and #14 of 105 in Kansas. Since the April 1, 2020 estimates base of 34,191, the population has grown by 2,049 (+6%), compared with +1.3% for Kansas as a whole.

With 575.9 square miles of land, that is 63 people per square mile (24 per km²), placing Miami County #1,354 nationally for density and #11 in Kansas. The median county equivalent has 47 people per square mile; the Kansas median is 8.1. Put another way, there are about 10 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate34,22434,64934,75835,39135,80136,240
Change—+425+109+633+410+439

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 Miami County

5 incorporated places lie at least partly in Miami County. Together they are home to 19,675 people (54.3%); the other 16,565 (45.7%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Paola city, with 5,880 residents in the county. By land, Spring Hill city is the largest at 10.2 mi² across all its counties. Among places with at least 1,000 residents in 2020, Spring Hill city grew fastest since then (+34.2%).

Incorporated placePopulation 2025Since 2020Land mi²
Paola cityCounty seat5,880+1.9%5.299
Louisburg city5,299+6.7%4.879
Osawatomie city4,215+0.4%5.156
Spring Hill cityAlso in 1 other county4,047+34.2%10.2
Fontana city234+4%0.9

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

Metropolitan area

Miami County is an outlying county of the Kansas City, MO-KS Metropolitan Statistical Area. Its 14 county equivalents have 2,270,682 residents on 7,256.8 square miles of land; Miami County accounts for 7.9% of the land and 1.6% of the residents. By combined land it ranks #25 of 393 metropolitan areas, and #31 by population. It belongs to the Kansas City-Overland Park-Kansas City, MO-KS Combined Statistical Area.

County equivalentPopulation 2025Land mi²
Jackson CountyMissouri732,994604.7
Johnson County636,906473.6
Clay CountyMissouri265,032397.7
Wyandotte County170,597151.6
Cass CountyMissouri115,859696.6
Platte CountyMissouri114,400419.8
Leavenworth County84,590463.4
Miami County36,240575.9
Lafayette CountyMissouri33,531628.3
Ray CountyMissouri23,398569
Clinton CountyMissouri21,661418.9
Bates CountyMissouri16,512836.7
Linn County9,950594.1
Caldwell CountyMissouri9,012426.4

ZIP codes

11 ZIP Code Tabulation Areas have land in Miami County; 6 of them have most of their land inside the county, and the others mainly cover neighboring areas.

6601366021660266604066042660536606466071660726608366092

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 Miami County

Miami County shares a land border with 5 county equivalents, including 2 in Missouri. It has more land than 2 of them. The largest neighbor is Bates County (836.7 mi²) and the smallest is Johnson County (473.6 mi²). Together with its neighbors, Miami County forms a block of 3,748.7 mi² of land, of which it holds 15.4%.

Map of Miami County and the 5 county equivalents that border it Franklin County, Kansas: 571.8 mi² landLinn County, Kansas: 594.1 mi² landJohnson County, Kansas: 473.6 mi² landCass County, Missouri: 696.6 mi² landBates County, Missouri: 836.7 mi² land
Miami 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. MiamiCompare
Bates CountyMissouri836.71.5× largerCompare
Cass CountyMissouri696.61.2× largerCompare
Linn County594.1about the sameCompare
Franklin County571.8about the sameCompare
Johnson County473.61.2× smallerCompare

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

Miami County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.8 times as much. Kansas’s county land could hold about 142 areas the size of Miami County.

Land area: Miami County and the closest-sized states
Miami County575.9 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 24 miles (38.6 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 Miami County?

Miami County has more land than 1,502 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Miami County575.9 mi²
Kansas median729.7 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 Miami County at #1,781 nationally by total area, 61 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 2.4%, compared with a national county-equivalent median of 1.2% — 1.3 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 Miami County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#1719Greene County, Pennsylvania575.9Compare
#1720Miami County, Kansas575.9This county
#1721Franklin County, Nebraska575.8Compare

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 38.566771, -94.832966. 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: 1,491,523,008 m²; AWATER: 37,231,297 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 Miami County?

Miami County, Kansas has 575.9 square miles (1,491.5 km²) of land and 14.4 square miles of water, for a total area of 590.3 square miles. It ranks #1720 of 3,222 U.S. county equivalents by land area.

Is Miami County the largest county in Kansas?

No. Miami County ranks #88 of 105 in Kansas by land area. The largest is Butler County, with 1,429.7 square miles of land.

What counties border Miami County?

Miami County shares a land border with Franklin County, Linn County, Johnson County, Cass County, Missouri, and Bates County, Missouri.

What is the population of Miami County?

The Census Bureau estimates Miami County had 36,240 residents on July 1, 2025, ranking #1,321 of 3,222 county equivalents. That is 63 people per square mile of land.

What is the county seat of Miami County?

The county seat of Miami County is Paola.

What cities and towns are in Miami County?

Miami County has 5 incorporated places. The most populous are Paola city, Louisburg city, Osawatomie city, Spring Hill city, and Fontana city; 16,565 residents live outside any incorporated place.

Is Miami County part of a metropolitan area?

Yes. It is an outlying county of the Kansas City, MO-KS Metropolitan Statistical Area, which has 14 county equivalents and 2,270,682 residents.

How many ZIP codes are in Miami County?

11 ZIP Code Tabulation Areas have land in Miami County, and 6 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

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

It has less land than every state. Rhode Island, the smallest, has 1.8 times as much land.

How many acres of land are in Miami County?

The land measurement converts to approximately 368,563 acres. Including water, total area is approximately 377,763 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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