Mercer County GIS Maps
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Mercer County, New Jersey, has 387,340 residents across 142,344 parcels and covers 224.4 square miles. The population grew 5.7% between the 2010 and 2020 census. More residents moved in than left over that decade. The FIPS code for Mercer County is 34021.
Trenton is the county's largest population center. Mercer County also includes 22 zip codes, 9 public school districts and 33 municipalities. Those boundaries help explain why population, schools, and housing can look different from one part of the county to another. The map below shows how those county lines, zip codes, and school districts fit together, and the sections that follow use that same geography to show parcel data, population, demographics, school enrollment and housing patterns in more detail.
Maps, GIS layers, Parcels and sample data. Paid packages add full layers, analytics and database files.
Mercer County Trends
- Population
- 387,340▴
- Median Home Value
- $351,000▴
- K-12 Enrollment
- 57,171▴
County analytics dashboards with historical trends & projections included in package downloads.
Free starter access previews county maps, lightweight GIS, and sample data. Paid packages unlock full GIS layers, analytics, and database files.
Mercer County Maps
The maps below show a few of the county map styles included in our downloads. County packages include map exports in JPEG, PNG, SVG, PDF and GeoTIFF formats plus more than 20 GIS layers for mapping, research and analysis. Available layers include zip codes, area codes, subdivisions, school districts, political boundaries, roads, water features, points of interest and more.
County packages also include historical county demographics, business intelligence, analytical dashboards, AI-ready prompts, markdown files and related reference data. Everything is organized to save hours of manual work collecting current data, cleaning it and joining it together. That makes it easier to move faster on analytics, due diligence, business planning and location research. Paid packages are built for commercial use, but some package contents include source-specific attribution or notice guidance. Review Licensing & Data Source Notices.
Mercer County Parcels
Mercer County has 142,344 mapped parcels covering 132,586 acres. The median assessed value is $210,400. The median lot size is 0.18 acres. 2,508 parcels are 10 acres or larger. Of the parcels with a recorded build year, half were built in 1960 or earlier. About 6% of parcels list an owner mailing address outside New Jersey. Mailing addresses reach 89.4%. Site addresses reach 89.4%. Browse the interactive Mercer County Parcel viewer here.
Mercer County Parcel Data Coverage
| Field | Parcels | Coverage |
|---|---|---|
| Parcel ID | 142,344 | 100% |
| Owner name | 0 | 0% |
| Owner mailing address | 127,185 | 89.4% |
| Site address | 127,186 | 89.4% |
| Land use code | 127,186 | 89.4% |
| Land use description | 121,998 | 85.7% |
| Assessed value | 127,186 | 89.4% |
| Land value | 127,186 | 89.4% |
| Improvement value | 127,186 | 89.4% |
| Acreage | 127,186 | 89.4% |
| Parcel boundary | 142,344 | 100% |
| Download all Mercer County parcels. | ||
Field coverage measured across all Mercer County parcel records.
Mercer County Population
Mercer County had 387,340 residents in 2020. That was 5.7% higher than in 2010. Mercer County added 36,579 people between 2000 and 2020, which points to steady long-term growth. The county is fairly spread out, with about 1,726 people per square mile. Some of the county's most populated postal areas include Princeton, Trenton and Trenton.
Population Trend in Mercer County NJ
Mercer County Population per 2000, 2010 and 2020 census counts with a baseline 2030 projection.
Mercer County Zip Codes
Mercer County has 22 zip codes. Some of the county's most populated zip codes include Princeton (08540), Trenton (08618) and Trenton (08610). Princeton is the largest zip by population, with about 48,216 residents or 12% of the county total. Together, the three largest zips account for about 31% of all county residents based on 2020 population estimates.
Most Populated Zip Codes in Mercer County NJ
| ZIP | Area | Population | Trend |
|---|---|---|---|
| 08540 | Princeton | 48,216 | ▴ 2.3% |
| 08618 | Trenton | 37,544 | ▾ -1.8% |
| 08610 | Trenton | 32,649 | ▴ 7.2% |
| 08648 | Lawrence Township | 31,955 | ▾ -1% |
| 08611 | Trenton | 31,531 | ▴ 12.5% |
| Download all zip code data | |||
Mercer County Zip Code populations and trends per most recent census data.
Mercer County Demographics
Mercer County has a median age of 39.2, which makes the county a little younger than New Jersey overall. About 21.9% of residents are under 18, while 15.7% are 65 or older. That gives the county a fairly even mix of younger families and older adults. The largest age group is 25 to 44 at about 32% of the population, which points to a solid working-age base. About 44.9% of adults have a bachelor's degree or higher, above the statewide figure of 42.9%. The county has a more diverse population mix, with no single race or ethnicity accounting for all of the local story.
Key Demographics for Mercer County NJ
Median Age
39.2
Under 18
21.9%
Age 65+
15.7%
Bachelor's+
44.9%
Mercer County School Districts
Mercer County is served by 9 public school districts with 57,171 students enrolled in 2024. The largest districts on the county map are Trenton City, Hamilton Township and West Windsor-Plainsboro Regional. Those three districts account for about 61% of public school enrollment in the map area. Total enrollment has grown modestly since 2017 across the districts shown on the county map.
Largest School Districts by Enrollment in Mercer County NJ
| District | Enrollment | Share | Trend |
|---|---|---|---|
| Trenton City School District | 13,549 | 23.7% | ▴ 3.4% |
| Hamilton Township School District | 12,355 | 21.6% | ▴ 0.9% |
| West Windsor-Plainsboro Regional School District | 8,831 | 15.4% | ▾ -1.3% |
| East Windsor Regional School District | 5,006 | 8.8% | ▾ -2.2% |
| Lawrence Township School District | 3,690 | 6.5% | ▾ 0% |
| Download all school district data | |||
Mercer County school district enrollment and trends per most recent NCES reporting data.
Mercer County Housing & Real Estate
Mercer County has a median home value of $351,000 and a median gross rent of $1,515. About 62% of occupied homes in the county are owner-occupied, so the local housing market leans heavily toward ownership. Home values run below the New Jersey median, while rents come in below the state average. In March 2026, the median listing price was $439,900 and homes spent about 40 days on the market.
Mercer County Housing Mix
Mercer County housing mix: owner, renter and vacant units.
Mercer County Housing Trends
Mercer County median home value and rent trend (last 5 years).
Businesses in Mercer County, NJ
Mercer County has 14,786 business listings across 947 categories. The largest categories in Mercer County business listings are Churches & Religious Organizations (317, 2.1%), Real Estate Agents (304, 2.1%), and Community & Nonprofits (252, 1.7%). The full Mercer County business listings dataset includes names, categories, addresses and contact details where available. Mercer County packages also include U.S. Census County Business Patterns data with establishment counts, employment and payroll by industry sector.
Top Business Categories in Mercer County, NJ
| Category | Businesses | Share |
|---|---|---|
| Churches & Religious Organizations | 317 | 2.1% |
| Real Estate Agents | 304 | 2.1% |
| Community & Nonprofits | 252 | 1.7% |
| Medical Offices | 224 | 1.5% |
| Landmark And Historical Building | 199 | 1.3% |
| Parks & Recreation | 175 | 1.2% |
| Auto Repair | 170 | 1.1% |
| ATMs | 169 | 1.1% |
| Hair Salons | 165 | 1.1% |
| Contractors | 157 | 1.1% |
Mercer County Business Listings
| Business | Category | City |
|---|---|---|
| US1 Printing Solutions | 3D Printing Service | Princeton |
| Summit Behavioral Health Princeton Junction | Abuse And Addiction Treatment | Princeton Junction |
| Rider University Bookstore | Academic Bookstore | Lawrence Twp |
| Frutta Bowls | Acai Bowls | Robbinsville |
| Lakeside Apartments | Accommodation | Princeton |
| John M Vlasac & Company | Accountant | Trenton |
| Jasna Polana Country Club Estate | Active Life | Princeton |
| Hamilton West Windsor Acupuncture | Acupuncture | Trenton |
| Drug Detox Trenton | Addiction Rehabilitation Center | Trenton |
| Children's Home Society of New Jersey | Adoption Services | Trenton |
| Download Mercer County business listings | ||
Mercer County business listings sourced from Overture Maps. Includes locations with a high level of confidence.
Mercer County Basemaps
Mercer County map and data packages include a set of useful basemaps to help you get started quickly. These include a custom light grey canvas, USGS topo, imagery and other reference layers that make it easier to build clear, meaningful county maps using the included GIS layers, your own data or both. Pre-rendered map tiles for the light grey basemap are included so you can use them offline or host them on your own CDN.
Get the Full Mercer County Data Package
This page shows a preview of what's included in the Mercer County data package. The full package gives you a ready-to-use county data system with GIS layers, historical data, maps, database files and planning tools that save hours of manual data gathering, cleanup and joins. Everything is organized to help you skip data wrangling and start analysis faster.
- 20+ GIS layers for parcels, zip codes, school districts, roads, water, boundaries and more
- Historical county demographics, housing, income and trend data
- ZIP code population files and school district enrollment history
- Database files, markdowns, AI-ready prompts and documentation
- Map exports in PNG, JPEG, PDF, SVG and GeoTIFF formats
- Offline-ready data explorer, map and analytics tools
Paid packages support commercial use, client work, and derived outputs. Some package contents may include source-specific attribution or provider notices. See Licensing & Data Source Notices.
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Nearby Counties
Browse county data pages for the counties that border Mercer County. These nearby pages include the same mix of county maps, demographic summaries, school district context, housing trends and package links.