Latitude and Longitude to UTM Converter
Enter a latitude and longitude (decimal degrees or DMS) and this converter returns the full UTM coordinate: zone number, latitude band letter, easting in metres, northing in metres, grid convergence, and the point scale factor. The step-by-step panel shows the exact Transverse Mercator arithmetic behind each number, and the reference table maps every latitude band to its degree range. All calculations use the WGS-84 ellipsoid, the same datum used by GPS.
What is UTM?
The Universal Transverse Mercator (UTM) coordinate system is a global map projection that divides the Earth into 60 longitudinal zones, each 6 degrees wide, running from pole to pole. Within each zone, a Transverse Mercator projection is applied with a central meridian down the middle of the zone. Instead of degrees, UTM expresses position as metres east (easting) and metres north (northing) of a defined origin. This makes distance and area calculations simple and accurate across most of the globe - it is the standard system for topographic maps, military navigation, land surveying, GIS, and GPS receivers worldwide.
How lat/long to UTM conversion works
Converting geographic coordinates (latitude, longitude on the WGS-84 ellipsoid) to UTM involves four stages. First, the zone number is determined from the longitude: zone = floor((lon + 180) / 6) + 1, with special-case zones in southern Norway (zone 32) and Svalbard (zones 31-37). Second, the central meridian lon0 = (zone - 1) x 6 - 180 + 3 is computed, and the longitude offset from it gives the delta-lambda. Third, the meridional arc M from the equator to the latitude is calculated using a power-series expansion of the ellipsoidal arc length. Fourth, easting and northing are computed from a truncated Transverse Mercator series in delta-lambda; a false easting of 500,000 m is added so all easting values are positive, and southern-hemisphere points add a false northing of 10,000,000 m for the same reason. The standard UTM scale factor k0 = 0.9996 is applied to reduce distortion across the zone.
Grid convergence and scale factor
Two quantities accompany every UTM coordinate that are important for precise work. Grid convergence is the angle at a point between true north (the direction to the geographic North Pole) and grid north (the direction parallel to the central meridian on the map). It depends on how far east or west of the central meridian you are and how far from the equator. For points near the central meridian it is near zero; it grows toward the edges of the zone and at higher latitudes. When converting compass bearings to grid bearings, or vice versa, the convergence must be applied. The point scale factor k measures how much distances are distorted at a given point by the projection. On the central meridian k = k0 = 0.9996, meaning distances are 400 parts per million too short. About 180 km from the central meridian k rises to approximately 1.0, and at the zone edges it can reach about 1.001.
Special UTM zones and polar limits
Most of the world uses the regular 6-degree zone grid, but three exceptions exist. Zone 32 is widened at the expense of zone 31 between 56 N and 64 N to give all of Norway (including its western coast) a single consistent zone. In the Svalbard/Spitsbergen region (72 N to 84 N), zones 32 and 34 are eliminated and zones 31, 33, 35, and 37 are widened to 9-12 degrees to keep the archipelago in one zone. The UTM system only covers latitudes from 80 S to 84 N; the polar caps use the UPS (Universal Polar Stereographic) system instead. Trying to convert coordinates beyond those limits will return an empty result in this calculator.
UTM latitude band letters
| Band | Latitude range | Hemisphere | Notes |
|---|---|---|---|
| C | -80 to -72 | South | |
| D | -72 to -64 | South | |
| E | -64 to -56 | South | |
| F | -56 to -48 | South | |
| G | -48 to -40 | South | |
| H | -40 to -32 | South | |
| J | -32 to -24 | South | |
| K | -24 to -16 | South | |
| L | -16 to -8 | South | |
| M | -8 to 0 | South | |
| N | 0 to 8 | North | |
| P | 8 to 16 | North | |
| Q | 16 to 24 | North | |
| R | 24 to 32 | North | |
| S | 32 to 40 | North | |
| T | 40 to 48 | North | |
| U | 48 to 56 | North | |
| V | 56 to 64 | North | |
| W | 64 to 72 | North | |
| X | 72 to 84 | North | 12 degrees tall; special zones 31-37 apply |
The UTM system divides the earth into 20 latitudinal bands, each 8 degrees tall (except band X which is 12 degrees). The letters I and O are omitted to avoid confusion with numerals.
Frequently asked questions
What is the UTM coordinate system?
UTM (Universal Transverse Mercator) divides the Earth into 60 longitudinal zones of 6 degrees each. Within each zone, a Transverse Mercator projection is applied and positions are expressed in metres north (northing) and east (easting) of a defined origin. This makes it easy to measure distances and areas without converting degrees to metres, which is why it is standard in topographic mapping, land surveying, and GIS software.
What do the UTM zone number and band letter mean?
The zone number (1-60) identifies the 6-degree longitudinal strip your point falls in, starting at 180 degrees west. The band letter (C through X, skipping I and O) identifies one of the 20 eight-degree latitudinal bands. Together they form the Grid Zone Designator, for example "18T" for New York City. The hemisphere (N or S) indicates which false northing origin to use.
What is easting and northing in UTM?
Easting is the distance in metres east of a false origin placed 500,000 m west of the central meridian, so all easting values in a zone are positive (ranging from about 166,000 m to 834,000 m). Northing is the distance in metres north of the equator (for the northern hemisphere) or north of a false origin placed 10,000,000 m south of the equator (for the southern hemisphere), ensuring northing is always positive too.
What datum does this calculator use?
All calculations use the WGS-84 (World Geodetic System 1984) reference ellipsoid, which is the datum used by GPS satellites and virtually all modern mapping software. If your source coordinates are on a different datum (such as NAD27 or ED50), you need to apply a datum transformation before using this converter.
Why does UTM not work above 84 N or below 80 S?
The Transverse Mercator projection becomes increasingly distorted as you approach the poles, so UTM is formally defined only between 80 S and 84 N. The polar regions use a different projection, the Universal Polar Stereographic (UPS) system, centered on each pole. The small asymmetry (80 S vs 84 N) exists for historical reasons related to the original military grid.
What is grid convergence and why does it matter?
Grid convergence is the angle between true north (toward the geographic North Pole) and grid north (parallel to the central meridian on the map) at a specific point. It is zero on the central meridian and grows toward the zone edges and at higher latitudes. Surveyors, pilots, and orienteers must apply this correction when converting between compass bearings and map grid bearings.
What is the point scale factor?
The point scale factor (k) indicates how much horizontal distances measured on the ground are distorted by the map projection at your specific location. On the central meridian k = 0.9996, meaning distances are 400 ppm too short (about 40 cm per km). Roughly 180 km from the central meridian k = 1.0 (no distortion). At the zone edges k can reach approximately 1.001. Multiply a ground distance by k to get the grid distance, or divide by k to go the other way.