MO · GEOID 29510

St. Louis city area

St. Louis city, Missouri covers 66.2 square miles: 61.7 square miles of land and 4.5 square miles of water.

Official Census measurements2026 Gazetteer · retrieved September 27, 2026
Land area61.7 mi²
Water area4.5 mi²
Total area66.2 mi²
National land rank#3111

County outline

Generalized outline of St. Louis city, 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 St. Louis city is located

St. Louis city highlighted on a map of all U.S. county equivalents. About the maps

Area breakdown

Land accounts for 93.3% of St. Louis city’s measured area and water for 6.7%. Its combined area converts to 171.4 square kilometers or approximately 42,349 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land61.717159.84639,498.9
Water4.45411.5362,850.6
Total66.171171.38242,349.4

How St. Louis city compares

By original Census land area, St. Louis city ranks #115 of 115 in Missouri and #3111 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 0.104 times the Missouri county-equivalent median of 592 square miles. It accounts for 0.1% of the combined county land area in the state.

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

What stands out about St. Louis city?

St. Louis city has more land than 111 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
St. Louis city61.7 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 St. Louis city at #3,137 nationally by total area, 26 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 6.7%, compared with a national county-equivalent median of 1.2% — 5.6 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 St. Louis city in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#3110Orocovis Municipio, Puerto Rico63.6Compare
#3111St. Louis city, Missouri61.7This county
#3112Lares Municipio, Puerto Rico61.4Compare

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 38.635699, -90.244582. 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: 159,847,392 m²; AWATER: 11,534,972 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 St. Louis city?

The land measurement converts to approximately 39,499 acres. Including water, total area is approximately 42,349 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