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GPS Coordinate Converter

Converters · Added

Paste a coordinate in whatever form you have it and get all three notations back. The parser copes with degree symbols, primes, hemisphere letters and signs, and it tells you which reading it used when the input could have been taken more than one way.

Any of the three notations, with or without hemisphere letters. Latitude first where there are no letters.

Try:

How to use the gps coordinate converter

  1. 1Paste the coordinate — 40.4462, -79.9822 and 40°26'46"N 79°58'56"W are both understood.
  2. 2Read the three formatted results and copy whichever one you need.
  3. 3Check the note about hemispheres if your input had no N/S/E/W letters.
  4. 4Use the precision table to decide how many decimal places you actually need.

Examples

DMS into decimal degrees

Input
40°26'46.3"N 79°58'55.9"W
Result
40.446194, -79.982194

A southern-hemisphere pair

Input
-33.8688, 151.2093
Result
33°52'07.7"S 151°12'33.5"E

The negative latitude becomes an S; the positive longitude becomes an E.

About the gps coordinate converter

Why three notations survive

Decimal degrees won everywhere software is involved, because it is one number and arithmetic on it is trivial. Degrees, minutes and seconds survive in surveying and cartography, where the sexagesimal division is baked into the instruments and the archives. Degrees with decimal minutes is the aviation and marine standard, and it is what most handheld receivers display by default.

None of them is more accurate than another. They are the same quantity written three ways, and converting between them loses nothing except where the number of digits is cut short.

Where the seconds go wrong

Converting to degrees, minutes and seconds means rounding, and rounding each part separately is how a coordinate ends up reading 40°26'60". Sixty seconds is a minute; the reading is not far wrong but it is not something anybody writes.

The fix is to round the seconds first and then carry upwards — sixty seconds becomes a minute, sixty minutes becomes a degree. That is what happens here, which is why the seconds field never shows 60.

Frequently asked questions

Which value is the latitude if there are no letters?
The first one. Latitude first is the convention in plain text, in ISO 6709 and on every consumer mapping service. The trap is GeoJSON, which puts longitude first — so a pair copied out of a GeoJSON file will look transposed here, and the result panel flags that it made the assumption.
What if the number is negative and there is also a W or an S?
The letter wins and the magnitude of the number is used. Writing both a sign and a letter is genuinely ambiguous, and treating the letter as authoritative is what a GPS receiver does. The result says which rule it applied rather than leaving you to guess.
How many decimal places do I need?
Five is a doorway, six is finer than a consumer GPS can fix. Four places is about eleven metres, which identifies a building; three is about a hundred metres, which identifies a street. The table on the page gives the whole scale — and those distances hold exactly for latitude everywhere, but for longitude only at the equator, since a degree of longitude narrows towards the poles.
Do the three formats all describe the same point?
Yes, to the precision shown. What can differ is the datum underneath them: these all assume WGS-84, which is what GPS and every modern map uses. A coordinate lifted from an older survey on a national datum can sit hundreds of metres from its WGS-84 position, and no amount of reformatting will move it.

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