GPS UTM Coordinate Converter

GPS devices and web maps give positions as latitude and longitude in degrees. Surveyors, civil engineers and GIS users often need Universal Transverse Mercator (UTM) coordinates instead: a zone number plus easting and northing in metres. Metric grid coordinates make distances and areas easy to calculate on site. This converter transforms WGS84 latitude and longitude into UTM.

How to use it

1. Enter latitude and longitude in decimal degrees, for example 18.5204, 73.8567.
2. Read the UTM zone, hemisphere, easting and northing.

How UTM works

• The world is divided into 60 zones, each 6° of longitude wide, numbered eastward from 180°W. Zone = floor((longitude + 180) / 6) + 1.
• Each zone uses its own transverse Mercator projection with a central meridian, keeping distortion low within the zone.
• Easting is metres from the central meridian plus a false easting of 500,000 m, so values are always positive.
• Northing is metres from the equator; in the southern hemisphere a false northing of 10,000,000 m is added.

Worked example

Pune, India, at latitude 18.5204° N and longitude 73.8567° E lies in zone floor(253.8567 / 6) + 1 = 43, northern hemisphere (43Q in latitude-band notation). Its UTM coordinates are approximately E 379,000 m, N 2,048,000 m.

Practical notes

• Always record the zone and hemisphere; the same easting and northing exist in every zone.
• Projects crossing a zone boundary should use a single zone, or a local grid, for consistent calculations.
• Norway and Svalbard have special zone exceptions.
• Coordinates are only as accurate as the input; consumer GPS is typically accurate to 3 to 5 m.