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Census Data for Round Hill

Population ...

The most recent Census Estimate<1> was for 2019 and it gave Round Hill a population of 658 people.

The last Decennial Census<2> was in 2010, which gave Round Hill a population of 539 people.

The town of Round Hill is located in Loudoun County. The 2010 Census gave Loudoun County; a population of 312,311 people. This means that Round Hill had 0.17% of the county's total population, making it Loudoun's 5th most populous community.

At the same time, Virginia had a population of 8,001,024 people.

Area ...

The 2010 Census shows that the sampling area for Round Hill has a total area of 0.37 square miles [1 km²]. Of this total, 0.37 square miles [0.9 km²] is land, with the balance (1.08%) being water (0 square miles [0 km²]).

Loudoun County has a land area of 515 square miles [1,335.3 km²]. At 0.37 square miles [0.9 km²], Round Hill has 0.07% of the county's total land area.

  • Continue Reading ...
    • When the Census Bureau conducts a census for a town like Round Hill, 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 town.
    • Things like population, area and housing for Round Hill reflect the sampling area. Since the shape of the sampling area and the actual boundaries of Round Hill 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:   39° 7' 54"   (or 39.13°)
    • Lon:   -77° 46' 5"   (or -77.77°)
    • 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, Round Hill had 218 Housing Units<3> and with its population of 539 people, this averages 2.47 people per Housing Unit.

  • Continue Reading ...
    • The 2010 Census shows Round Hill had a land area of 0.37 square miles [0.9 km²]. This translates to 589 Housing Units per square mile [227.5 housing units/km²].
    • From the Census of 2000: Round Hill had 177 Housing Units, a population of 500 people and a land area of 0.21 square miles [0.6 km²]. This gives a density of 2.82 people per Housing Unit and 826 Housing Units per square mile [319 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 Round Hill and you need to be careful when comparing values between the censuses. More information about these differences can be found in the section called Census-to-Census Observations ... (see below).

Loudoun County ...

The community of Round Hill is located in Loudoun County<4>.

The county had a population of 312,311 people at the 2010 Census. With it's population of 539 people, Round Hill represented 0.17% of the county's total.

In addition, where the town of Round Hill has a population density of 1,456 people per square mile [562 people/km²], Loudoun County averages 605 people per square mile [233.9 people/km²].

For more information, please visit our Census Page for Loudoun County.

Census-to-Census Observations ...

Introduction ...

When the Census Bureau takes a census count (or enumeration) for Round Hill, 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 Round Hill. 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 Round Hill 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 Round Hill, the latitude and longitude given by the Census Bureau actually indicates the GPS location of the polygon for Round Hill.

  • Continue Reading ...
    • For the 2010 Census, the location was given as:
    • Lat:   39.131857°   (or 39°7'54" N)
    • Lon:   -77.768083°   (or -77°46'5" W)
    • For the 2000 Census, the location given was:
    • Lat:   39.133625°   (or 39°8'1" N)
    • Lon:   -77.770217°   (or -77°46'12" W)
    • The difference indicates that the U.S. Census Bureau moved the location of the polygon for the 2010 Census 883 feet to the southeast<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 (#2391396) to Round Hill. This identifier also marks a GPS point on the map, and that point lies within the boundaries of Round Hill. The GNIS point has been mapped to the latitude/longitude:
    • Lat:   39.134179°   (or 39°8'3" N)
    • Lon:   -77.769146°   (or -77°46'8" W)
    • The GPS location given for the 2010 Census lies 898 feet to the south<6> of the point given by the GNIS for Round Hill. For more information about this and the relationship of the various Federal Codes, please visit our Misc Page for Round Hill.

Miscellaneous Information for Round Hill ...

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 Loudoun County or the town of Round Hill:

  • The GNIS Codes ...
    • The current system of identification is called the Geographic Names Information System (GNIS). The following GNIS codes relate to Round Hill:
    • GNIS ID for Round Hill: 2391396
    • GNIS ID for Loudoun County: 1480141
    • GNIS ID for State of Virginia: 1779803
  • Misc. Census Codes ...
    • Round Hill is located in Census Region #3 (the South Region) and Division #5 (the South Atlantic Division).

For more information about the various Federal identification codes, please visit our Misc Page for Round Hill.

The official website for Round Hill:

The official website for Loudoun County:

The official website for State of Virginia:

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 Virginia's counties, including Loudoun, have changed over time, we recommend the Atlas of Historical County Boundaries.
<5>The calculated bearing (or angle) to the 2010 Census location is 223 degrees and a distance of 883 feet.
<6>The calculated bearing (or angle) to the GNIS point is 199 degrees and a distance of 898 feet.


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This page was last modified/updated: 04 Dec 2023