What a UTM coordinate is made of
The Universal Transverse Mercator system divides the world between 80°S and 84°N into 60 zones, each 6° of longitude wide, and projects each zone onto a flat grid measured in metres. A UTM coordinate therefore has three parts:
- Zone — a number from 1 to 60, usually followed by a latitude band letter (C to X) or a hemisphere (N/S).
- Easting — metres from a false origin 500,000 m west of the zone’s central meridian.
- Northing — metres from the equator; in the southern hemisphere 10,000,000 m is added so values stay positive.
New York: 18T 583959 4507351 — zone 18, band T, easting 583,959 m, northing 4,507,351 m.
UTM to latitude and longitude
Paste the zone, easting and northing in almost any layout — 18T 583959 4507351, 18N 583959mE 4507351mN or Zone 18, 583,959 E, 4,507,351 N. Without a band letter the point is read as northern hemisphere; add S (for example 33S) for the south. The letters N and S are ambiguous (they are also band letters) — the converter checks which reading fits and tells you which one it used.
Zone exceptions
Zone 32V is widened to cover western Norway, and zones 31X–37X are rearranged around Svalbard. The converter applies both exceptions automatically. UTM is not defined beyond 84°N or 80°S; polar areas use the UPS system instead.
Accuracy
Conversions use the Krüger series on the WGS 84 ellipsoid, accurate to well under a millimetre inside a zone. Note that UTM distances are slightly scaled (scale factor 0.9996 on the central meridian), so measured lengths differ from ground distance by up to about 0.1% near zone edges.
Frequently asked questions
How do I find my UTM zone?
Zone = floor((longitude + 180) / 6) + 1, with special cases for Norway and Svalbard. Enter any latitude and longitude and the converter shows the zone and latitude band.
Why does my UTM northing look so large in the southern hemisphere?
Southern-hemisphere northings include a false northing of 10,000,000 m so that every value is positive.
Can I convert UTM coordinates without the zone?
No. The same easting and northing exist in all 60 zones, so a UTM coordinate is incomplete without its zone number and hemisphere or band.