Convert UTM to latitude and longitude

Converting UTM to lat long takes three things: the easting, the northing and the zone with its hemisphere. Pick the zone in From, paste the two numbers and the table gives WGS 84 latitude and longitude, in decimal degrees and in degrees, minutes and seconds. The point 580735.87, 4504695.17 in zone 18N is the Statue of Liberty: 40.6892000, -74.0445000.

1. Pick the UTM zone of your coordinates in From, with its hemisphere. The page opens on WGS 84 / UTM zone 18N, which covers New York and most of the US East Coast; London is in 30N and New Delhi in 43N. To is already WGS 84, latitude and longitude.
2. Paste the coordinates, one point per line: easting first, then northing, in metres, separated by a comma, a space or a tab. If a line starts with its zone, such as 18T 580735 4504695, the page offers to switch to that zone in one click.
3. Read the latitude and longitude in the table, in decimal degrees and in degrees, minutes and seconds. Copy the results or download them as CSV, and check each point on the map.

Three points converted with this tool. Each one sits in a different zone: pick the zone of the second column in From before pasting the line.

The zone cannot be read from the two numbers: it has to come with them, on the plan, in the file header or in the GPS settings. Each zone is 6 degrees of longitude wide. The contiguous United States runs from zone 10 on the Pacific coast to zone 19 in Maine, Great Britain uses zones 29 to 31 and India zones 42 to 47. A wrong zone moves the point by a multiple of 6 degrees.

South of the equator 10,000,000 m are added to the northing so that it is never negative, so the same pair of numbers means two very different places north and south. Mind the letter after the zone number: in 18T, the T is a latitude band, not the hemisphere. Bands C to M are in the south and N to X in the north.

US survey and state data are usually NAD83, GPS units give WGS 84. The two differ by one to two metres in the contiguous United States, which this page does not correct: it reads the numbers as WGS 84. For mapping at street level that is fine. For survey work, apply the NAD83 to WGS 84 transformation your agency publishes and keep the datum stated next to the result.

Each zone gives 500,000 m to its central meridian, so eastings stay positive and run from about 166,000 to 834,000 m. Northings are the distance from the equator in metres, seven digits at most. A pair such as 4504695, 580735 is simply in the other order: change it in More options.

Yes. Paste one point per line, or drop a CSV file, and every line is converted in your browser. A label after the two numbers is kept in the table and in the CSV you download.