Universal Transverse Mercator (UTM) Coordinate System

Caitlin Dempsey

Updated:

Universal Transverse Mercator (UTM) is a coordinate system that is widely used for mapping and navigation purposes.

The UTM coordinate system is a system of grids that is used to locate positions on the earth’s surface.

UTM: 60 longitudinal zones

UTM divides the earth into 60 longitudinal zones, each of which is 6 degrees wide. The zones are numbered from 1 to 60, starting from the international date line in the Pacific Ocean and moving eastward. Related: How to Calculate the Boundaries of an UTM Zone

The UTM system provides a way to accurately locate a position on the earth’s surface by specifying the zone and the easting and northing coordinates within that zone.


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A shaded relief map of the contiguous United Stated with medium grey lines showing UTM zones.
UTM zones over the United States. Map: Caitlin Dempsey.

Development of the UTM system

The UTM system was adopted by the US Army in 1947, and it has since been adopted as an international standard. The system is used by many different organizations, including the military, government agencies, and private companies. It is particularly useful for navigation purposes, as it provides an accurate and standardized way to locate positions on the earth’s surface.

The UTM grid system is based on the Transverse Mercator projection, which is a type of cylindrical map projection. In this projection, the Earth’s surface is projected onto a cylinder that is tangent to the earth’s surface at a particular latitude.

The cylinder is then unrolled to form a flat map. The UTM grid system uses a series of these cylindrical projections that are tangent to different latitudes. Each of the 60 longitudinal zones has its own cylindrical projection.

How the UTM grid system is divided

The UTM grid system divides each zone into a series of squares, with each square measuring 100,000 meters (or 100 kilometers) on each side.

These squares are called UTM grid zones. The easting and northing coordinates of a position within a UTM grid zone are measured in meters, with the origin (0,0) located at the southwest corner of the zone.

A screenshot showing an attribute window with the values for a UTM grid.
The UTM values for UTM grid zones.

Locate a position using UTM coordinates

To locate a position on the Earth’s surface using UTM coordinates, you need to know the zone in which the position is located. You also need to know the easting and northing coordinates of the position within that zone.

The easting coordinate is measured from the west edge of the zone, and the northing coordinate is measured from the south edge of the zone.

A section of a US topo map showing contour lines and UTM and geographic coordinates.
US Topo map showing latitude and longitude of the corner (38°N, -115.8750°W) and brown UTM gridlines (4,206,000 meters northing and 599,000 meters easting). Map: USGS, public domain.

For example, the UTM coordinates for the Eiffel Tower in Paris, France are:

UTM Easting448,265.91
UTM Northing5,411,920.65

The “448265” indicates that the tower is located 448,265 meters east of the west edge of the zone, and the “5411920” indicates that the tower is located 5,411,920 meters north of the south edge of the zone.

How is UTM different than the latitude and longitude coordinate system?

UTM (Universal Transverse Mercator) is a coordinate system that is different from the latitude and longitude coordinate system. While both are used to identify locations on Earth, they have some key differences:

  1. Representation:
    • Latitude and longitude are based on a spherical coordinate system, where positions are represented by angles. Latitude measures the angle north or south of the equator, while longitude measures the angle east or west of the Prime Meridian.
    • UTM is a Cartesian coordinate system that divides the Earth into 60 zones, each 6 degrees wide in longitude. Within each zone, locations are represented by a pair of (x, y) coordinates, where x is the easting (distance east from a central meridian) and y is the northing (distance north or south from the equator).
  2. Units:
    • Latitude and longitude are measured in degrees, minutes, and seconds (DMS) or decimal degrees (DD).
    • UTM coordinates are measured in meters.
  3. Distortion and accuracy:
    • Latitude and longitude coordinates suffer from distortion, especially when measuring distances and areas, as the Earth is not a perfect sphere.
    • UTM coordinates, on the other hand, use a series of map projections to minimize distortion within each zone. This makes UTM more suitable for accurate distance and area calculations in smaller regions.

Converting between UTM and other coordinate systems

One of the benefits of the UTM system is that it provides a way to convert between different coordinate systems. For example, if you have the latitude and longitude of a position on the Earth’s surface, you can use a UTM conversion tool to convert those coordinates to UTM coordinates.

This is useful when you want to use a map that is based on the UTM grid system to navigate to a location that is specified using latitude and longitude.

Uses for the UTM coordinate system

The UTM system is widely used in a variety of applications, including surveying, mapping, and navigation. It is particularly useful for military applications, as it provides a standardized way to locate positions on the earth’s surface that can be easily communicated between different units.

The UTM system is also used in GPS devices, which can provide real-time location information based on UTM coordinates.

Advantages of the UTM coordinate system

One of the advantages of the UTM system is that it provides a standardized way to locate positions on the Earth’s surface that can be easily communicated between different organizations.

This is particularly important in military applications where coordination between different units is critical. The UTM system is also widely used in surveying and mapping applications, as it provides an accurate and consistent way to locate positions on the earth’s surface.

Another advantage of the UTM system is that it can be easily converted to other coordinate systems, such as latitude and longitude. This makes it easy to use UTM-based maps in conjunction with GPS devices, which typically use latitude and longitude coordinates. UTM conversion tools are widely available and can be used to convert between different coordinate systems.

Limitations of the UTM coordinate system

Despite its many advantages, the UTM system does have some limitations. One limitation is that it is based on a cylindrical projection, which can result in distortions in scale and shape in certain areas.

Distortion in high latitudes with UTM

This can be a problem in areas with high latitude, where the distortion can be significant. To address this issue, different projections, such as the Universal Polar Stereographic (UPS) projection, may be used in areas with high latitude.

UTM can only be used for small areas

Another limitation of the UTM system is that it does not take into account the curvature of the earth’s surface. This means that the UTM system is not suitable for precise calculations over long distances.

For applications that require precise calculations over long distances, such as satellite navigation, other coordinate systems, such as geodetic coordinate systems, may be used.

UTM: a widely used coordinate system

In summary, the Universal Transverse Mercator (UTM) system is a widely used coordinate system that provides an accurate and consistent way to locate positions on the earth’s surface.

UTM is based on a grid system of squares and uses a series of cylindrical projections to cover different longitudinal zones. While the UTM system has some limitations, it is a useful tool for a variety of applications, including surveying, mapping, and navigation.

Quick facts about the Universal Transverse Mercator (UTM) system:

  • The UTM system was adopted by the US Army in 1947 for military navigation and mapping purposes.
  • The earth is divided into 60 longitudinal zones, each of which is 6 degrees wide in longitude.
  • Each UTM zone is divided into a grid of squares, with each square measuring 100,000 meters on each side.
  • The UTM system uses the Transverse Mercator projection, which is a cylindrical map projection.
  • The UTM system provides a standardized way to locate positions on the earth’s surface, which is useful for military, surveying, mapping, and navigation applications.
  • UTM coordinates are expressed as a zone number, an easting coordinate, and a northing coordinate.
  • The UTM system is widely used in GPS devices and can be easily converted to other coordinate systems, such as latitude and longitude.
  • The UTM system does have some limitations, such as distortions in scale and shape in certain areas and lack of consideration for the curvature of the earth’s surface over long distances.
  • The U.S. Military uses an adapted version of UTM called the Military Grid Reference System (MGRS)

References

Moore, L. (1997). Transverse mercator projections and US Geological Survey digital products. US Geological Survey, Professional Paper. http://www.geo.utexas.edu/courses/420k/PDF_files/LABS/GIS/map_project.pdf

Hager, J. W., Behensky, J. F., & Drew, B. W. (1989). The universal grids: Universal transverse mercator (UTM) and universal polar stereographic (UPS). Edition 1. Defense Mapping Agency Hydrographic/Topographic Center Washington DC.

The Universal Transverse Mercator (UTM) grid (Report No. 157–99; Fact Sheet, p. 2). (1999). USGS Publications Warehouse. https://doi.org/10.3133/fs15799

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About the author
Caitlin Dempsey
Caitlin Dempsey is the editor of Geography Realm and holds a master's degree in Geography from UCLA as well as a Master of Library and Information Science (MLIS) from SJSU.