San Lorenzo Municipio area

San Lorenzo Municipio, Puerto Rico covers 53.2 square miles: 53.1 square miles of land and 0.099 square miles of water. Its county seat is San Lorenzo. An estimated 37,275 people lived there in 2025.

Official Census measurements · GEOID 721292026 Gazetteer · retrieved September 27, 2026
Land area53.1 mi²
Water area0.099 mi²
Population (2025)37,275
People per mi²702

County outline

Generalized outline of San Lorenzo Municipio, Puerto Rico
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 San Lorenzo Municipio is located

San Lorenzo Municipio highlighted on a map of all U.S. county equivalents. Puerto Rico is repositioned as an inset at the common scale. About the maps

Area breakdown

Land accounts for 99.8% of San Lorenzo Municipio’s measured area and water for 0.2%. Its combined area converts to 137.8 square kilometers or approximately 34,055 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land53.112137.55933,991.7
Water0.0990.25663.4
Total53.211137.81634,055

How San Lorenzo Municipio compares

By original Census land area, San Lorenzo Municipio ranks #22 of 78 in Puerto Rico and #3125 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 1.265 times the Puerto Rico county-equivalent median of 42 square miles. It accounts for 1.6% of the combined county land area in the state.

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

Population and density of San Lorenzo Municipio

The Census Bureau estimates that 37,275 people lived in San Lorenzo Municipio on July 1, 2025. That ranks #1,286 of 3,222 county equivalents nationally and #28 of 78 in Puerto Rico. Since the April 1, 2020 estimates base of 37,691, the population has declined by 416 (−1.1%), compared with −3.1% for Puerto Rico as a whole.

With 53.1 square miles of land, that is 702 people per square mile (271 per km²), placing San Lorenzo Municipio #259 nationally for density and #45 in Puerto Rico. The median county equivalent has 47 people per square mile; the Puerto Rico median is 754. Put another way, there are about 0.912 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate37,67037,63037,23337,22337,34337,275
Change—−40−397−10+120−68

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 San Lorenzo Municipio

Puerto Rico has no incorporated places below the municipio: San Lorenzo Municipio is itself the local government. The Census Bureau describes the settlements inside it, such as zonas urbanas and comunidades, as statistical places, and publishes no separate annual estimates for them.

Metropolitan area

San Lorenzo Municipio is a central county of the San Juan-Bayamón-Caguas, PR Metropolitan Statistical Area. Its 40 county equivalents have 2,024,195 residents on 1,437.8 square miles of land; San Lorenzo Municipio accounts for 3.7% of the land and 1.8% of the residents. By combined land it ranks #229 of 393 metropolitan areas, and #36 by population. It belongs to the San Juan-Bayamón, PR Combined Statistical Area.

ZIP codes

4 ZIP Code Tabulation Areas have land in San Lorenzo Municipio; 1 of them have most of their land inside the county, and the others mainly cover neighboring areas.

00725007540077700778

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 San Lorenzo Municipio

San Lorenzo Municipio shares a land border with 6 county equivalents. It has more land than 4 of them. The largest neighbor is Caguas Municipio (58.6 mi²) and the smallest is Juncos Municipio (26.5 mi²). Together with its neighbors, San Lorenzo Municipio forms a block of 301.8 mi² of land, of which it holds 17.6%.

Map of San Lorenzo Municipio and the 6 county equivalents that border it Caguas Municipio, Puerto Rico: 58.6 mi² landYabucoa Municipio, Puerto Rico: 55.2 mi² landJuncos Municipio, Puerto Rico: 26.5 mi² landPatillas Municipio, Puerto Rico: 46.6 mi² landGurabo Municipio, Puerto Rico: 27.9 mi² landLas Piedras Municipio, Puerto Rico: 33.9 mi² land
San Lorenzo Municipio (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. San LorenzoCompare
Caguas Municipio58.61.1× largerCompare
Yabucoa Municipio55.2about the sameCompare
Patillas Municipio46.61.1× smallerCompare
Las Piedras Municipio33.91.6× smallerCompare
Gurabo Municipio27.91.9× smallerCompare
Juncos Municipio26.52× smallerCompare

How big is San Lorenzo Municipio compared with U.S. states?

San Lorenzo Municipio has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 19 times as much. Puerto Rico’s county land could hold about 64 areas the size of San Lorenzo Municipio.

Land area: San Lorenzo Municipio and the closest-sized states
San Lorenzo Municipio53.1 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 7.29 miles (11.7 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 San Lorenzo Municipio?

San Lorenzo Municipio has more land than 97 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
San Lorenzo Municipio53.1 mi²
Puerto Rico median42 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 San Lorenzo Municipio at #3,152 nationally by total area, 27 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 0.2%, compared with a national county-equivalent median of 1.2% — 1 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 San Lorenzo Municipio in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#3124Norfolk city, Virginia53.3Compare
#3125San Lorenzo Municipio, Puerto Rico53.1This county
#3126Cayey Municipio, Puerto Rico51.9Compare

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 18.146921, -65.976915. 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: 137,559,503 m²; AWATER: 256,428 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 San Lorenzo Municipio?

San Lorenzo Municipio, Puerto Rico has 53.1 square miles (137.6 km²) of land and 0.099 square miles of water, for a total area of 53.2 square miles. It ranks #3125 of 3,222 U.S. county equivalents by land area.

Is San Lorenzo Municipio the largest county in Puerto Rico?

No. San Lorenzo Municipio ranks #22 of 78 in Puerto Rico by land area. The largest is Arecibo Municipio, with 126 square miles of land.

What counties border San Lorenzo Municipio?

San Lorenzo Municipio shares a land border with Caguas Municipio, Yabucoa Municipio, Juncos Municipio, Patillas Municipio, Gurabo Municipio, and Las Piedras Municipio.

What is the population of San Lorenzo Municipio?

The Census Bureau estimates San Lorenzo Municipio had 37,275 residents on July 1, 2025, ranking #1,286 of 3,222 county equivalents. That is 702 people per square mile of land.

What is the county seat of San Lorenzo Municipio?

The county seat of San Lorenzo Municipio is San Lorenzo.

Is San Lorenzo Municipio part of a metropolitan area?

Yes. It is a central county of the San Juan-Bayamón-Caguas, PR Metropolitan Statistical Area, which has 40 county equivalents and 2,024,195 residents.

How many ZIP codes are in San Lorenzo Municipio?

4 ZIP Code Tabulation Areas have land in San Lorenzo Municipio, and 1 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

How does San Lorenzo Municipio compare with U.S. states?

It has less land than every state. Rhode Island, the smallest, has 19.5 times as much land.

How many acres of land are in San Lorenzo Municipio?

The land measurement converts to approximately 33,992 acres. Including water, total area is approximately 34,055 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