International · Geodesy

UTM to lat/long.

Convert UTM coordinates to WGS84 latitude and longitude, or latitude and longitude to UTM. Give the zone with either a latitude band letter or a hemisphere. It follows the Norway (32V) and Svalbard (31X to 37X) zone exceptions. Everything runs in your browser and nothing you type is sent or stored.

WGS84 · k0 0.9996 False easting 500,000 m · false northing 10,000,000 m in the south

Inputs

Direction

Zone (1 to 60)

Zone letter given as

Band letter C to M are south of the equator, N to X north. I and O are not used.

Easting (m)

Northing (m) Or paste a full reference such as 17T 630087 4833442 into the zone box.

Result

Enter a coordinate and press Convert.

How UTM converts to latitude and longitude

UTM splits the world between 80°S and 84°N into 60 zones, each 6° of longitude wide, and projects every zone with a transverse Mercator projection on the WGS84 ellipsoid. The central meridian of zone z is 6z − 183 degrees. The scale on the central meridian is 0.9996, easting is measured from a false origin of 500,000 m, and southern-hemisphere northings add a false northing of 10,000,000 m so no value goes negative.

The zone letter is a latitude band: C to M lie south of the equator and N to X north of it (I and O are skipped, and each band is 8° tall except X, which is 12°). A UTM reference can therefore say “17T” (band) or “17 N” (hemisphere). Note that the letter N in a band reference means the band from 0° to 8°N; use the hemisphere option to say “northern hemisphere”.

Two exceptions change the zone number: band V in zone 32 is widened to cover 3°E to 12°E (south-west Norway), and band X uses zones 31, 33, 35 and 37 only, covering 0–9°E, 9–21°E, 21–33°E and 33–42°E (Svalbard). Zones 32X, 34X and 36X do not exist.

The projection uses the Krüger series in the third flattening n carried to order six, as set out by Karney (2011). Against Karney’s published 287,000-point test set this implementation agrees to about 5 nanometres, and it matches PROJ’s UTM output to better than a nanometre on the check points. That is far finer than any GPS receiver, so the limit on real accuracy is your input, not the maths. Datum matters: this tool is WGS84 (and so NAD83 to within about a metre). Older datums such as NAD27 or ED50 give shifts of tens to hundreds of metres.

Sources

C. F. F. Karney, Transverse Mercator with an accuracy of a few nanometers, J. Geodesy 85 (2011), the series and coefficients used here.
Karney, Test data for the transverse Mercator projection (Zenodo), used to verify the projection.
PROJ, Universal Transverse Mercator (k0, false origins, zone numbering), and PROJ 9.8.1 outputs used as an independent check.
Wikipedia, Universal Transverse Mercator coordinate system for the band letters and the Norway and Svalbard exceptions.

Scope of this converter

This is a coordinate calculation, not a survey. It assumes WGS84 and the standard UTM grid, and it does not apply datum shifts, geoid heights or polar (UPS) coordinates. Check a result against your own control points before using it for anything that matters. Runs entirely in your browser: nothing you type is transmitted, stored, or logged.