Coordinate Systems & Converters

Latitude and longitude are the address system of the planet, but they come in several written formats — and this collection converts between them. The Coordinate Converter takes a latitude and longitude in decimal degrees and expresses them as degrees, minutes and seconds (DMS) and as UTM zone, easting and northing. The DMS to Decimal Degrees Converter runs the reverse direction for people copying coordinates out of nautical charts, survey documents or older GPS readouts, while the Decimal Degrees to DMS Converter goes the other way. The UTM Converter works with the Universal Transverse Mercator grid system, the MGRS Converter handles Military Grid Reference System coordinates, the Plus Code Converter encodes locations as Open Location Codes, and the Coordinate Format Converter rounds out the set for switching between notations.

All of these are interactive: enter decimal-degree values, get the converted result instantly, computed in your browser. There is no account, no upload and no waiting — the math runs locally. If you are pasting coordinates from a spreadsheet or a field notebook, check whether your numbers use a comma or a dot as the decimal separator first; mixing them up is the most common reason a conversion "looks wrong".

Three guides explain the ideas behind the tools. The latitude and longitude guide starts from zero: what the two angles measure, why the equator and the prime meridian are where they are, and how to read a coordinate aloud. The UTM guide explains the zone system — sixty six-degree slices of the Earth — and when a grid reference is more practical than a lat/long pair. The map projections article tackles the deeper problem these tools sit on top of: every flat map distorts the round Earth somewhere, and the choice of projection decides whether shapes, areas, distances or directions are preserved.

Together the tools and guides cover the practical side of coordinate literacy: reading coordinates, writing them correctly, converting between the formats professionals use, and understanding why maps of the same place can look so different.