Sheet 1 · Coordinate converter
Paste a position in decimal degrees, degrees-minutes-seconds, degrees and decimal minutes, UTM or MGRS. The format is recognised and you get all the others, on the WGS84 datum GPS uses.
Latitude and longitude are angles: latitude north or south of the equator (−90° to +90°), longitude east or west of the Greenwich meridian (−180° to +180°). The same angle can be written as decimal degrees (48.8582°), degrees and decimal minutes (48° 51.492′) or degrees, minutes and seconds (48° 51′ 29.52″). A degree has 60 minutes and a minute 60 seconds, so 0.8582° × 60 = 51.492′, and 0.492′ × 60 = 29.52″.
UTM (Universal Transverse Mercator) projects the earth onto 60 zones, each 6° of longitude wide, and measures in metres: an easting from a false origin 500 km west of the zone's central meridian, and a northing from the equator, plus 10,000 km in the southern hemisphere. MGRS, the grid NATO forces and many rescue teams use, writes the same position with two letters for the 100 km square, so 31 N 448251 5411932 becomes 31U DQ 48251 11932.
Every conversion uses the WGS84 ellipsoid, the datum of GPS. UTM is computed with Krüger's series as published by Karney in 2011, accurate to well under a millimetre within a zone, so a round trip from degrees to UTM and back returns the same position.
Four more sheets for working with positions, all on the same WGS84 ellipsoid.
Geodesic distance by Karney's method, checked against Vincenty and the haversine formula.
Initial and final bearing, compass point, rhumb-line course and the halfway point.
Where a bearing and a distance take you from any start, on the ellipsoid and the sphere.
Every letter and digit of an MGRS or UTM reference decoded, with zone and square diagrams.
Two free services for the online side of planning a trip.
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Try WebTraceCheckMGRS truncates rather than rounds: the reference names the 1 m square the point falls in. Some devices round instead, which can move the last digit by one.
Latitude, in nearly every format and map app. GeoJSON and some software put longitude first. If you add N, S, E or W, the converter sorts them out whichever order you type.
Degrees work everywhere. UTM and MGRS stop at 84°N and 80°S; the polar caps use the Universal Polar Stereographic grid, which this page does not convert.