Census Data for Trenton
Population ...
The most recent Census Estimate<1> was for 2019 and it gave Trenton a population of 83,375 people.
The last Decennial Census<2> was in 2010, which gave Trenton a population of 84,913 people.
The city of Trenton is located in Mercer County. The 2010 Census gave Mercer County; a population of 366,513 people. This means that Trenton had 23.17% of the county's total population, making it Mercer's most populous community.
At the same time, New Jersey had a population of 8,791,894 people, meaning that Trenton had 0.97% of the total population of New Jersey - making it the state's 5th most populous community.
Area ...
The 2010 Census shows that the sampling area for Trenton has a total area of 8.15 square miles [21.1 km²]. Of this total, 7.65 square miles [19.8 km²] is land, with the balance (6.22%) being water (0.51 square miles [1.3 km²]).
Mercer County has a land area of 224.6 square miles [581.6 km²]. At 7.65 square miles [19.8 km²], Trenton has 3.41% of the county's total land area.
- Continue Reading ...
- When the Census Bureau conducts a census for a city like Trenton, they draw a boundary around the area in which they are going to conduct their count - this defines the sampling area (usually a polygon). The shape of the sampling area can be quite complex and it's important to keep in mind that the boundaries of the sampling area may or may not match the recognized boundaries of the city.
- Things like population, area and housing for Trenton reflect the sampling area. Since the shape of the sampling area and the actual boundaries of Trenton might be different, it's best to check with the U.S. Census Bureau to resolve any difference between the two.
- Not only does the sampling area define boundaries, it also has a GPS location (latitude & longitude) that indicates a point within the sampling area (usually the center of the polygon, known as the centroid). At the time of the 2010 Census, the sampling area was located at:
- Lat: 40° 13' 25" (or 40.22°)
- Lon: -74° 45' 50" (or -74.76°)
- More information on this topic and the changes between the 2000 Census and the 2010 Census can be found in the section for our Census-to-Census Observations ... (see below).
Housing Units ...
At the time of the 2010 Census, Trenton had 33,035 Housing Units<3> and with its population of 84,913 people, this averages 2.57 people per Housing Unit.
- Continue Reading ...
- The 2010 Census shows Trenton had a land area of 7.65 square miles [19.8 km²]. This translates to 4,050 Housing Units per square mile [1,564 housing units/km²].
- From the Census of 2000: Trenton had 33,843 Housing Units, a population of 85,403 people and a land area of 7.66 square miles [19.8 km²]. This gives a density of 2.52 people per Housing Unit and 4,154 Housing Units per square mile [1,604 housing units/km²].
- Note: Repeating the caution above (under Population Density), be aware that when comparing Housing Units between the 2010 and the 2000 Census, there were changes in the sampling area for Trenton and you need to be careful when comparing results between the censuses. More information about the nature of these the changes can be found in the section called Census-to-Census Observations ... (see below).
Mercer County ...
The city of Trenton is located in Mercer County<4> and is the County Seat for Mercer County.
The county had a population of 366,513 people at the 2010 Census. With it's population of 84,913 people, Trenton represented 23.17% of the county's total.
In addition, where the city of Trenton has a population density of 10,412 people per square mile [4,020 people/km²], Mercer County averages 1,632 people per square mile [630 people/km²].
For more information, please visit our Census Page for Mercer County.
Census-to-Census Observations ...
Introduction ...
When the Census Bureau takes a census count (or enumeration) for Trenton, they start by specifying the boundaries of the area to be counted. This area (or sampling area) is a polygon and its shape can be quite complex - it may or may not match the geographical boundaries of Trenton. It's important to note that from one Census to the next, the shape and location of the polygon can change.
- Continue Reading ...
- Although we don't have specific information about the shape of the polygon for Trenton or how it changed has over time, there is some information that can give us some hints. For example, since the shape of the sampling area is directly related to the shape of the polygon, any change to area probably indicates a new shape for the polygon.
- If you need precision or details about the methodology of the Census, you should visit the U.S. Census Bureau for a definitive answer.
Location ...
While generally coinciding with the GPS location (latitude/longitude) of Trenton, the latitude and longitude given by the Census Bureau actually indicates the GPS location of the polygon for Trenton.
- Continue Reading ...
- For the 2010 Census, the location was given as:
- Lat: 40.223748° (or 40°13'25" N)
- Lon: -74.764001° (or -74°45'50" W)
- For the 2000 Census, the location given was:
- Lat: 40.221741° (or 40°13'18" N)
- Lon: -74.756138° (or -74°45'22" W)
- The difference indicates that the U.S. Census Bureau moved the location of the polygon for the 2010 Census 2,307 feet to the west<5> of the location that was used in the 2000 Census.
- The U.S. Geological Survey (USGS) and the U.S. Board on Geographic Names (BGN) have assigned a unique GNIS identifier (#885421) to Trenton. This identifier also marks a GPS point on the map, and that point lies within the boundaries of Trenton. The GNIS point has been mapped to the latitude/longitude:
- Lat: 40.223442° (or 40°13'24" N)
- Lon: -74.763773° (or -74°45'49" W)
- The GPS location given for the 2010 Census lies 128.4 feet to the northwest<6> of the point given by the GNIS for Trenton. For more information about this and the relationship of the various Federal Codes, please visit our Misc Page for Trenton.
Miscellaneous Information for Trenton ...
The Federal government has assigned various identifying codes to each community, county and state. At one time or another, the US Census Bureau has used one (or more) of the following identifiers when referring to either Mercer County or the city of Trenton:
- The GNIS Codes ...
- The FIPS Codes ...
- An earlier (and largely obsolete) identification method was called the Federal Information Processing Standard (FIPS):
- State Code: 34 (New Jersey)
- County Code: 021 (Mercer County)
- Place Code: 74000 (Trenton)
- State & County Code: 34/021 (New Jersey / Mercer County)
- State & Place Code: 34/74000 (New Jersey / Trenton)
- Misc. Census Codes ...
- Trenton is located in Census Region #1 (the Northeast Region) and Division #2 (the Middle Atlantic Division).
For more information about the various Federal identification codes, please visit our Misc Page for Trenton.
Off-the-Road Links ...
The official website for Trenton: www.ci.trenton.nj.us/
The official website for Mercer County: www.mercercounty.org/
The official website for State of New Jersey: https://www.state.nj.us/
The official website of the U.S. Census Bureau
The official website of the U.S. Board on Geographic Names (BGN)
The official website of the U.S. Geological Survey (USGS)
Footnotes ...
| <1> | Every year, the US Census Bureau creates a population estimate for the preceeding year. Keep in mind that this value is an estimate and not an actual count. The most recent Census estimate is for the year 2019. |
| <2> | Every 10 years (eg- 1990, 2000, 2010), the US Census Bureau conducts a Constitutionally-mandated count (or enumeration) of people living within the United States. This count is called a Decennial Census. The last Decennial Census was the 2010 Census, with the next one planned for 2020. |
| <3> | A Housing Unit is a broad term for those places where people live (whether occupied or temporarily vacant), such as a house, an apartment, a mobile home, or an area that is considered as a separate living quarter. Separate living quarters (consisting of one or more rooms) are considered to be those places where people live, sleep and eat separately from others and that have access to the outside (either directly or by a shared hallway). |
| <4> | If you're interested in how the shape of New Jersey's counties, including Mercer, have changed over time, we recommend the Atlas of Historical County Boundaries. |
| <5> | The calculated bearing (or angle) to the 2010 Census location is 71 degrees and a distance of 2,307 feet. |
| <6> | The calculated bearing (or angle) to the GNIS point is 29 degrees and a distance of 128.4 feet. |