Dev · Converter
DMS to decimal degrees converter & lat/long validator.
Paste a latitude and a longitude in any common format, such as 43°38'33.2"N, 43 38.553 N or 43.6426. You get decimal degrees, degrees-minutes-seconds, degrees-decimal-minutes and a GeoJSON position, with range checks. Everything runs in your browser; nothing is stored or sent.
Inputs
Result
Enter a latitude and longitude and press Convert.
How the conversion works
There are 60 minutes in a degree and 60 seconds in a minute, so decimal degrees = degrees + minutes/60 + seconds/3600, negated for south latitudes and west longitudes. Going back, the whole part is the degrees, the whole part of 60 × the fraction is the minutes, and what is left over is the seconds. This is the method described on Wikipedia's geographic coordinate conversion page.
Worked example from that page: 40° 26′ 46″ N is 40 + 26/60 + 46/3600 = 40.446111, and 79° 58′ 56″ W is −79.982222. In degrees-decimal-minutes the same points are 40° 26.767′ N and 79° 58.933′ W.
Valid ranges and coordinate order
Latitude runs from −90 to 90 and longitude from −180 to 180; minutes and seconds must be below 60. Order matters: people usually say "latitude, longitude", but GeoJSON positions are [longitude, latitude] (RFC 7946, section 3.1.1). The result below gives the GeoJSON order so you can copy it straight in.
What this checks and doesn’t
This checks the format and numeric range of a coordinate and does the arithmetic. It cannot tell you whether the point is where you think it is, which datum it uses (WGS 84 is assumed), or whether anything exists there.