Census Data for West Mifflin

Population ...

The most recent Census Estimate<1> was for 2019 and it gave West Mifflin a population of 19,702 people.

The last Decennial Census<2> was in 2010, which gave West Mifflin a population of 20,313 people.

The community of West Mifflin is located in Allegheny County. The 2010 Census gave Allegheny County; a population of 1,223,957 people. This means that West Mifflin had 1.66% of the county's total population, making it Allegheny's 5th most populous community.

At the same time, Pennsylvania had a population of 12,702,379 people, meaning that West Mifflin had 0.16% of the total population of Pennsylvania - making it the state's 26th most populous community.

Area ...

The 2010 Census shows that the sampling area for West Mifflin has a total area of 14.51 square miles [37.6 km²]. Of this total, 14.21 square miles [36.8 km²] is land, with the balance (2.03%) being water (0.29 square miles [0.8 km²]).

Allegheny County has a land area of 730 square miles [1,890.9 km²]. At 14.21 square miles [36.8 km²], West Mifflin has 1.95% of the county's total land area.

• Continue Reading ...
  • When the Census Bureau conducts a census for a community like West Mifflin, 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 community.
  • Things like population, area and housing for West Mifflin reflect the sampling area. Since the shape of the sampling area and the actual boundaries of West Mifflin 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° 21' 27"   (or 40.36°)
  • Lon:   -79° 54' 19"   (or -79.91°)
  • 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, West Mifflin had 9,462 Housing Units<3> and with its population of 20,313 people, this averages 2.15 people per Housing Unit.

• Continue Reading ...
  • The 2010 Census shows West Mifflin had a land area of 14.21 square miles [36.8 km²]. This translates to 652 Housing Units per square mile [251.8 housing units/km²].
  • From the Census of 2000: West Mifflin had 9,966 Housing Units, a population of 22,464 people and a land area of 14.16 square miles [36.7 km²]. This gives a density of 2.25 people per Housing Unit and 690 Housing Units per square mile [266.8 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 West Mifflin and you need to be careful when comparing between the censuses. More information about the changes can be found in the section called Census-to-Census Observations ... (see below).

Allegheny County ...

West Mifflin is located in Allegheny County<4>.

The county had a population of 1,223,957 people at the 2010 Census. With it's population of 20,313 people, West Mifflin represented 1.66% of the county's total.

In addition, where the community of West Mifflin has a population density of 1,400 people per square mile [540 people/km²], Allegheny County averages 1,676 people per square mile [647 people/km²].

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

Census-to-Census Observations ...

Introduction ...

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

• Continue Reading ...
  • For the 2010 Census, the location was given as:
  • Lat:   40.357663°   (or 40°21'27" N)
  • Lon:   -79.905401°   (or -79°54'19" W)
  • For the 2000 Census, the location given was:
  • Lat:   40.368089°   (or 40°22'5" N)
  • Lon:   -79.897633°   (or -79°53'51" W)
  • The difference indicates that the U.S. Census Bureau moved the location of the polygon for the 2010 Census 4,370 feet to the southwest<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 (#1214837) to West Mifflin. This identifier also marks a GPS point on the map, and that point lies within the boundaries of West Mifflin. The GNIS point has been mapped to the latitude/longitude:
  • Lat:   40.367292°   (or 40°22'2" N)
  • Lon:   -79.897272°   (or -79°53'50" W)
  • The GPS location given for the 2010 Census lies 4,174 feet to the southwest<6> of the point given by the GNIS for West Mifflin. For more information about this and the relationship of the various Federal Codes, please visit our Misc Page for West Mifflin.

Miscellaneous Information for West Mifflin ...

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 Allegheny County or the community of West Mifflin:

• The GNIS Codes ...
  • The current system of identification is called the Geographic Names Information System (GNIS). The following GNIS codes relate to West Mifflin:
  • GNIS ID for West Mifflin: 1214837
  • GNIS ID for Allegheny County: 1213657
  • GNIS ID for Commonwealth of Pennsylvania: 1779798

• The FIPS Codes ...
  • An earlier (and largely obsolete) identification method was called the Federal Information Processing Standard (FIPS):
  • State Code: 42 (Pennsylvania)
  • County Code: 003 (Allegheny County)
  • Place Code: 83512 (West Mifflin)
  • State & County Code: 42/003 (Pennsylvania / Allegheny County)
  • State & Place Code: 42/83512 (Pennsylvania / West Mifflin)

• Misc. Census Codes ...
  • West Mifflin is located in Census Region #1 (the Northeast Region) and Division #2 (the Middle Atlantic Division).

• The US Postal Service ZIP Code ...
  • While some people have used ZIP codes to identify a community, the ZIP codes were actually created to make mail delivery more efficient by grouping addresses together. Although a ZIP Code doesn't specifically identify a community like West Mifflin, they do identify addresses that are in (or near) the community. It's important to remember that the boundaries of the ZIP Code can be changed, re-assigned, eliminated or overlapped with other ZIP Codes.
  • Our list of ZIP codes for West Mifflin:<7>
  •  & .

• Census ZCTA Codes ...
  • The US Census Bureau created statistical entities that they call ZIP Code Tabulation Areas (ZCTAs) and these ZCTAs are frequently confused with the ZIP codes that come from the US Postal Service (USPS).
  • ZCTAs were first created for the 2000 Census and at that time, they were based upon the USPS ZIP codes. While largely covering the same areas, the boundaries of a ZCTA do not necessarily match the boundaries of a postal ZIP code with the same number. For example, while a postal ZIP code can cross a county or state line, a Census ZCTA can not. They should be treated as separate entities with no correlation between them.

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