Arecibo Municipio area

Arecibo Municipio, Puerto Rico covers 171.2 square miles: 126 square miles of land and 45.2 square miles of water. Its county seat is Arecibo. An estimated 85,539 people lived there in 2025.

Official Census measurements · GEOID 720132026 Gazetteer · retrieved September 27, 2026
Land area126 mi²
Water area45.2 mi²
Population (2025)85,539
People per mi²679

County outline

Generalized outline of Arecibo 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 Arecibo Municipio is located

Arecibo 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 73.6% of Arecibo Municipio’s measured area and water for 26.4%. Its combined area converts to 443.4 square kilometers or approximately 109,574 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land126.04326.44280,665.6
Water45.17116.9928,908.8
Total171.21443.432109,574.4

How Arecibo Municipio compares

By original Census land area, Arecibo Municipio ranks #1 of 78 in Puerto Rico and #3079 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 3.001 times the Puerto Rico county-equivalent median of 42 square miles. It accounts for 3.7% 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 Arecibo Municipio

The Census Bureau estimates that 85,539 people lived in Arecibo Municipio on July 1, 2025. That ranks #699 of 3,222 county equivalents nationally and #7 of 78 in Puerto Rico. Since the April 1, 2020 estimates base of 87,744, the population has declined by 2,205 (−2.5%), compared with −3.1% for Puerto Rico as a whole.

With 126 square miles of land, that is 679 people per square mile (262 per km²), placing Arecibo Municipio #263 nationally for density and #46 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 0.943 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate87,65287,16086,09485,68285,82885,539
Change—−492−1,066−412+146−289

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 Arecibo Municipio

Puerto Rico has no incorporated places below the municipio: Arecibo 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

Arecibo Municipio is a central county of the Arecibo, PR Metropolitan Statistical Area. Its 4 county equivalents have 179,229 residents on 236.9 square miles of land; Arecibo Municipio accounts for 53.2% of the land and 47.7% of the residents. By combined land it ranks #390 of 393 metropolitan areas, and #256 by population. It belongs to the San Juan-Bayamón, PR Combined Statistical Area.

County equivalentPopulation 2025Land mi²
Arecibo Municipio85,539126
Hatillo Municipio37,81041.7
Camuy Municipio32,69146.4
Quebradillas Municipio23,18922.7

ZIP codes

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

0061200616006500065200688

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 Arecibo Municipio

Arecibo Municipio shares a land border with 5 county equivalents. It has more land than every one of them. The largest neighbor is Utuado Municipio (113.6 mi²) and the smallest is Florida Municipio (15.2 mi²). Together with its neighbors, Arecibo Municipio forms a block of 381.8 mi² of land, of which it holds 33%.

Map of Arecibo Municipio and the 5 county equivalents that border it Hatillo Municipio, Puerto Rico: 41.7 mi² landUtuado Municipio, Puerto Rico: 113.6 mi² landBarceloneta Municipio, Puerto Rico: 18.7 mi² landFlorida Municipio, Puerto Rico: 15.2 mi² landCiales Municipio, Puerto Rico: 66.6 mi² land
Arecibo 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. AreciboCompare
Utuado Municipio113.61.1× smallerCompare
Ciales Municipio66.61.9× smallerCompare
Hatillo Municipio41.73× smallerCompare
Barceloneta Municipio18.76.7× smallerCompare
Florida Municipio15.28.3× smallerCompare

How big is Arecibo Municipio compared with U.S. states?

Arecibo Municipio has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 8.2 times as much. Puerto Rico’s county land could hold about 27 areas the size of Arecibo Municipio.

Land area: Arecibo Municipio and the closest-sized states
Arecibo Municipio126 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 11.2 miles (18.1 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 Arecibo Municipio?

Arecibo Municipio has more land than 143 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Arecibo Municipio126 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 Arecibo Municipio at #3,063 nationally by total area, 16 places closer to the top than its land rank. The water assigned to this geography moves it ahead of some county equivalents with more land.

Its water share is 26.4%, compared with a national county-equivalent median of 1.2% — 25.2 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 Arecibo Municipio in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#3078Essex County, New Jersey126.1Compare
#3079Arecibo Municipio, Puerto Rico126This county
#3080Clarke County, Georgia119.3Compare

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 18.433966, -66.675213. 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: 326,441,312 m²; AWATER: 116,989,546 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 Arecibo Municipio?

Arecibo Municipio, Puerto Rico has 126 square miles (326.4 km²) of land and 45.2 square miles of water, for a total area of 171.2 square miles. It ranks #3079 of 3,222 U.S. county equivalents by land area.

Is Arecibo Municipio the largest county in Puerto Rico?

Yes. Arecibo Municipio has the most land of the 78 county equivalents in Puerto Rico.

What counties border Arecibo Municipio?

Arecibo Municipio shares a land border with Hatillo Municipio, Utuado Municipio, Barceloneta Municipio, Florida Municipio, and Ciales Municipio.

What is the population of Arecibo Municipio?

The Census Bureau estimates Arecibo Municipio had 85,539 residents on July 1, 2025, ranking #699 of 3,222 county equivalents. That is 679 people per square mile of land.

What is the county seat of Arecibo Municipio?

The county seat of Arecibo Municipio is Arecibo.

Is Arecibo Municipio part of a metropolitan area?

Yes. It is a central county of the Arecibo, PR Metropolitan Statistical Area, which has 4 county equivalents and 179,229 residents.

How many ZIP codes are in Arecibo Municipio?

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

How does Arecibo Municipio compare with U.S. states?

It has less land than every state. Rhode Island, the smallest, has 8.2 times as much land.

How many acres of land are in Arecibo Municipio?

The land measurement converts to approximately 80,666 acres. Including water, total area is approximately 109,574 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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