UTM to Lat/Long Converter — Northing & Easting ↔ Coordinates

How to convert UTM coordinates

What is UTM?

The Universal Transverse Mercator (UTM) coordinate system divides Earth into 60 north-south zones, each 6 degrees of longitude wide. Within each zone, locations are specified by two numbers: easting (meters east of a false origin) and northing (meters north of the equator). This produces flat, metric coordinates that make distance and area calculations trivially easy compared to angular latitude and longitude.

UTM was adopted by the United States Army in 1947 and later by NATO. Today it is the standard coordinate system for topographic mapping, land surveying, construction layout, GIS fieldwork, and military operations worldwide. If you have ever seen coordinates like “18T 583960 4507523” on a survey plat or military map, those are UTM coordinates.

UTM uses the Transverse Mercator projection, which wraps a cylinder around Earth touching along a meridian (the zone's central meridian) rather than the equator. This keeps distortion low within the narrow 6° strip. A scale factor of 0.9996 is applied at the central meridian, which means measurements there are 0.04% too small — but this reduces the maximum error at the zone edges, keeping the overall distortion within the zone below 0.04%.

UTM covers latitudes from 80°S to 84°N. The polar regions (above 84°N and below 80°S) use the Universal Polar Stereographic (UPS) system instead.

UTM zone reference

The 60 UTM zones each span 6° of longitude. Zone 1 starts at 180°W. Here are the first 10 and last 10 zones with their longitude ranges:

Zone letter reference

UTM latitude bands are designated by letters C through X, skipping I and O to avoid confusion with the numerals 1 and 0. Each band spans 8° of latitude, except band X which spans 12° (72°N to 84°N). Letters A and B are used for the Antarctic UPS region; Y and Z for the Arctic UPS region.

UTM vs Lat/Long

Both UTM and latitude/longitude describe positions on Earth, but they serve different purposes. Here is how they compare:

Worked examples

Five real-world conversions you can verify with this tool. Each shows the bidirectional result.

New York City (Central Park)

London (Big Ben)

Sydney (Opera House)

Tokyo (Tokyo Tower)

Eiffel Tower, Paris

What people use this tool for

Land surveying and construction

Surveyors and civil engineers work in UTM because meter-based coordinates integrate directly into CAD drawings and construction plans. When a property boundary or building corner is specified in decimal degrees from a GPS or web map, this converter bridges the gap to the metric UTM coordinates used in the field.

Military operations and MGRS

NATO and allied militaries report locations using MGRS, which is derived from UTM. This converter provides both UTM and MGRS output. For more coordinate formats including geohash and Plus Code, see the GPS coordinate converter.

GIS and mapping software

GIS professionals frequently need to convert between geographic coordinates (lat/long) and projected coordinates (UTM) when importing data into software like QGIS, ArcGIS, or PostGIS. This tool provides a quick sanity check for programmatic conversions and helps identify the correct UTM zone for a dataset.

Hiking and orienteering

Topographic maps from USGS and many national mapping agencies use UTM grid lines. Hikers and orienteers need to convert between the UTM grid references on their paper maps and the decimal coordinates shown by their GPS devices or phone apps. If you also need to plot coordinates on a map, try the latitude/longitude map tool.

Scientific fieldwork

Ecologists, geologists, and archaeologists often record field sample locations in UTM because the metric coordinates simplify distance calculations between sample points. When publishing data, they may need to convert to decimal degrees for use in web maps and databases. The latitude/longitude finder can help locate named places before converting to UTM.

Property and land records

Some county assessor offices and land registries record property corners in UTM coordinates. Homeowners and real estate professionals may need to convert these to lat/long to view the property on Google Maps or other web mapping platforms.

How UTM conversion works

UTM conversion involves mapping between angular geographic coordinates (latitude and longitude on the curved WGS84 ellipsoid) and planar metric coordinates (easting and northing on a flat map). The math uses the Transverse Mercator projection with specific parameters for each of the 60 zones.

WGS84 ellipsoid

The WGS84 datum models Earth as an ellipsoid with semi-major axis a = 6,378,137 m and flattening f = 1/298.257223563. From these, the eccentricity e = sqrt(2f - f²) and the second eccentricity e′ = e/sqrt(1-e²) are derived. All UTM math uses these constants.

Forward projection (Lat/Long to UTM)

Given latitude φ and longitude λ, the tool first determines the UTM zone (floor((λ+180)/6)+1, with Norway/Svalbard exceptions) and the central meridian λ0. It then computes the radius of curvature N, the tangent squared T, the second eccentricity term C, the longitude difference A, and the meridional arc M. Easting and northing are calculated using a series expansion truncated at A&sup5; (easting) and A&sup6; (northing), with scale factor k0 = 0.9996 and false easting of 500,000 m.

Reverse projection (UTM to Lat/Long)

The reverse starts by computing the footpoint latitude φ1 from the northing via the meridional arc inverse (using the e1 series). From φ1, it computes N1, T1, C1, R1, and the easting difference D. Latitude and longitude are then recovered through another series expansion in D, truncated at D&sup6; and D&sup5; respectively.

Scale factor and false origins

The scale factor k0 = 0.9996 at the central meridian means distances are slightly compressed there (by 0.04%) but expanded toward the zone edges, keeping the overall distortion within the zone under 1 part in 2,500. The false easting of 500,000 m ensures all easting values are positive. In the southern hemisphere, a false northing of 10,000,000 m prevents negative northing values.

How this tool compares

Many online converters handle UTM, but they vary in features. Here is how SimpleMapLab compares to common alternatives:

Glossary

UTM (Universal Transverse Mercator)

A projected coordinate system that divides Earth into 60 zones, each 6° of longitude wide. Coordinates are expressed in meters as easting and northing.

Easting

The distance in meters east of a UTM zone’s false origin (500,000 m west of the central meridian). Values typically range from ~160,000 to ~834,000 m.

Northing

The distance in meters north of the equator. In the southern hemisphere, a false northing of 10,000,000 m is added to keep all values positive.

Zone

One of 60 longitudinal strips, each 6° wide, numbered 1 (180°W–174°W) to 60 (174°E–180°E). Each zone uses its own Transverse Mercator projection.

Transverse Mercator

A map projection where the cylinder is rotated 90° to be tangent along a meridian rather than the equator. Minimizes distortion along a narrow north-south strip.

False easting

An offset of 500,000 meters added to all UTM easting values so that coordinates west of the central meridian are still positive.

False northing

An offset of 10,000,000 meters added to UTM northing values in the southern hemisphere to avoid negative numbers.

WGS84

World Geodetic System 1984 — the reference ellipsoid used by GPS. Semi-major axis: 6,378,137 m. Flattening: 1/298.257223563.

MGRS (Military Grid Reference System)

A coordinate system derived from UTM that encodes location as a compact alphanumeric string. Used by NATO and emergency services.

Grid convergence

The angle between grid north (the UTM grid’s northward direction) and true north. Varies across a zone, zero at the central meridian.

Related tools and resources

For converting between all coordinate formats — including UTM, MGRS, geohash, and Plus Code — the GPS coordinate converter handles seven formats at once with auto-detection. It is the more general tool; this page is optimized specifically for UTM conversions.

To plot your converted coordinates on a map and share the result, use the latitude/longitude map tool. If you need to find coordinates for a named place rather than convert existing ones, the latitude and longitude finder geocodes place names, addresses, and landmarks.

For geocoding an address to lat/long coordinates, the address-to-coordinates tool handles full addresses and partial place names. Need the distance between your two UTM points? The distance between two places calculator computes great-circle distance using the Haversine formula.

To check elevation at your converted coordinates, the elevation finder retrieves height above sea level from the Open-Meteo elevation API.

Data sources & methodology

Frequently asked questions