Decimal Degrees to UTM Converter

How it is calculated

The tool takes WGS84 latitude and longitude in decimal degrees (north and east positive, south and west negative) and projects them with the standard transverse Mercator series: scale factor k0 = 0.9996, semi-major axis a = 6,378,137 m, flattening 1/298.257223563. The zone is floor((lon + 180) / 6) + 1, and the central meridian of that zone is (zone − 1) × 6 − 180 + 3 degrees.

Easting is measured from the central meridian with a false easting of 500,000 m. Northing is the distance from the equator, with 10,000,000 m added in the southern hemisphere. The built-in exceptions are applied: the widened zone 32 over southwest Norway and zones 31, 33, 35 and 37 over Svalbard. The result is a zone number plus a latitude band letter (C to X), such as 35T. Latitude must be between -80 and 84 and longitude between -180 and 180; otherwise there is no result. Easting and northing are in metres.

Common mistakes

• Entering degrees, minutes and seconds such as 41°00'30" instead of decimal degrees: the fields expect 41.0082, so convert first.
• Forgetting the sign of west longitudes and southern latitudes: New York is about -74 longitude, and omitting the minus sign puts the point in the wrong zone and hemisphere.
• Swapping latitude and longitude: values like 28.97 and 41.00 are both valid in either field, so the tool gives a result for a wrong location without warning.
• Reading the letter in 35T as a hemisphere: it is a latitude band, and bands C to M are southern while N to X are northern. Southern points show a northing already offset by 10,000,000 m.
• Using the output for polar areas: latitudes beyond 84°N or 80°S return no result, since UTM does not cover them. Points exactly on a zone edge can also have an easting far from 500,000 m, so check the zone before using the number on a map.