MO · GEOID 29047

Clay County area

Clay County, Missouri covers 408.7 square miles: 397.7 square miles of land and 11 square miles of water.

Official Census measurements2026 Gazetteer · retrieved September 27, 2026
Land area397.7 mi²
Water area11 mi²
Total area408.7 mi²
National land rank#2536

County outline

Generalized outline of Clay County, Missouri
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 Clay County is located

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

Area breakdown

Land accounts for 97.3% of Clay County’s measured area and water for 2.7%. Its combined area converts to 1,058.4 square kilometers or approximately 261,540 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land397.6641,029.945254,505
Water10.99228.4697,034.9
Total408.6561,058.414261,539.8

How Clay County compares

By original Census land area, Clay County ranks #111 of 115 in Missouri and #2536 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 0.672 times the Missouri county-equivalent median of 592 square miles. It accounts for 0.6% of the combined county land area in the state.

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

What stands out about Clay County?

Clay County has more land than 686 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Clay County397.7 mi²
Missouri median592 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 Clay County at #2,554 nationally by total area, 18 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 2.7%, compared with a national county-equivalent median of 1.2% — 1.5 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 Clay County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#2535Noble County, Ohio398Compare
#2536Clay County, Missouri397.7This county
#2537Orange County, North Carolina397.6Compare

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 39.315551, -94.421502. 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: 1,029,945,880 m²; AWATER: 28,468,708 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 Clay County?

The land measurement converts to approximately 254,505 acres. Including water, total area is approximately 261,540 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