IA · GEOID 19129

Mills County area

Mills County, Iowa covers 440.6 square miles: 437.4 square miles of land and 3.2 square miles of water.

Official Census measurements2026 Gazetteer · retrieved September 27, 2026
Land area437.4 mi²
Water area3.2 mi²
Total area440.6 mi²
National land rank#2315

County outline

Generalized outline of Mills County, Iowa
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 Mills County is located

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

Area breakdown

Land accounts for 99.3% of Mills County’s measured area and water for 0.7%. Its combined area converts to 1,141.3 square kilometers or approximately 282,012 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land437.4311,132.941279,955.8
Water3.2128.3192,055.7
Total440.6431,141.26282,011.5

How Mills County compares

By original Census land area, Mills County ranks #80 of 99 in Iowa and #2315 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 0.768 times the Iowa county-equivalent median of 569.6 square miles. It accounts for 0.8% of the combined county land area in the state.

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

What stands out about Mills County?

Mills County has more land than 907 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Mills County437.4 mi²
Iowa median569.6 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 Mills County at #2,386 nationally by total area, 71 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 0.7%, compared with a national county-equivalent median of 1.2% — 0.4 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 Mills County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#2314Muscatine County, Iowa437.4Compare
#2315Mills County, Iowa437.4This county
#2316Telfair County, Georgia437.3Compare

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 41.033703, -95.619101. 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: 1,132,940,496 m²; AWATER: 8,319,853 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 many acres of land are in Mills County?

The land measurement converts to approximately 279,956 acres. Including water, total area is approximately 282,012 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