UTM Zone & Grid Reference Calculator
Determine the UTM (Universal Transverse Mercator) zone number, central meridian, and hemisphere for any geographic coordinate.
Results
What is it?
The UTM system divides Earth into 60 vertical zones of 6 degrees longitude each, numbered 1-60 eastward from 180 degrees W. Within each zone, a Transverse Mercator projection gives a flat coordinate system with minimal distortion ? ideal for accurate local mapping. Zones are further divided into latitude bands C-X (excluding I and O).
How to use
Enter your decimal latitude and longitude coordinates. The calculator returns your UTM zone number (e.g. Zone 30N for most of the UK), the central meridian of that zone, and the hemisphere. The central meridian has a false easting of 500,000 m in UTM.
Example scenario
London (51.5 N, 0.0): UTM Zone = 30, central meridian = -3 degrees, Northern hemisphere. New York (40.7 N, -74.0): UTM Zone = 18, central meridian = -75 degrees, Northern hemisphere. Sydney (-33.9 S, 151.2 E): UTM Zone = 56, Southern hemisphere.
Pro tip
UTM is excellent for distance and area calculations within a zone ? coordinates are in metres from the origin. Avoid crossing zone boundaries in calculations; use a single zone extended or switch to a geographic coordinate system. The UK National Grid (OSGB36) is based on a single Transverse Mercator projection centred on 2 degrees W.