# Universal Transverse Mercator (UTM)¶

The Universal Transverse Mercator is a system of map projections divided into sixty zones across the globe, with each zone corresponding to 6 degrees of longitude.

 Classification Transverse cylindrical, conformal Available forms Forward and inverse, ellipsoidal only Defined area Within the used zone, but transformations of coordinates in adjacent zones can be expected to be accurate as well Alias utm Domain 2D Input type Geodetic coordinates Output type Projected coordinates

UTM projections are really the Transverse Mercator to which specific parameters, such as central meridians, have been applied. The Earth is divided into 60 zones each generally 6° wide in longitude. Bounding meridians are evenly divisible by 6°, and zones are numbered from 1 to 60 proceeding east from the 180th meridian from Greenwich with minor exceptions .

## Usage¶

Convert geodetic coordinate to UTM Zone 32 on the northern hemisphere:

```\$ echo 12 56 | proj +proj=utm +zone=32
687071.44       6210141.33
```

Convert geodetic coordinate to UTM Zone 59 on the southern hemisphere:

```\$ echo 174 -44 | proj +proj=utm +zone=59 +south
740526.32       5123750.87
```

## Parameters¶

### Required¶

+zone=<value>

Select which UTM zone to use. Can be a value between 1-60.

### Optional¶

+south

Add this flag when using the UTM on the southern hemisphere.

+approx

Use faster, less accurate algorithm for the Transverse Mercator.

+algo=auto/evenden_snyder/poder_engsager

Selects the algorithm to use. The hardcoded value and the one defined in proj.ini default to `poder_engsager`, that is the most precise one.

When using auto, a heuristics based on the input coordinate to transform is used to determine if the faster Evenden-Snyder method can be used, for faster computation, without causing an error greater than 0.1 mm (for an ellipsoid of the size of Earth)

Note that `+approx` and `+algo` are mutually exclusive.

+ellps=<value>

The name of a built-in ellipsoid definition.

See Ellipsoids for more information, or execute `proj -le` for a list of built-in ellipsoid names.

Defaults to "GRS80".