GPS Coordinates Converter
Convert coordinates between DD, DMS, and DDM formats instantly. Type in any field and the other formats update automatically.
Understanding Coordinate Formats
The same location on Earth can be written in three common formats. They all describe identical coordinates — only the notation differs.
Decimal Degrees (DD)
Latitude and longitude expressed as decimal numbers. Negative values indicate south or west.
Example
37.5665, 126.9780
Commonly used in
Web maps, GIS software, programming APIs, GPS data files
Degrees Minutes Seconds (DMS)
The traditional format dividing each degree into 60 minutes and each minute into 60 seconds.
Example
37°33'59.4"N 126°58'40.8"E
Commonly used in
Nautical charts, aviation, surveying, printed maps
Degrees Decimal Minutes (DDM)
A hybrid format using whole degrees with decimal minutes. Standard in marine and aviation GPS devices.
Example
37°33.990'N 126°58.680'E
Commonly used in
Marine navigation, aviation GPS, geocaching
What about UTM?
UTM (Universal Transverse Mercator) is a projected coordinate system that expresses positions in meters within zones instead of degrees. It is widely used in surveying and military applications. This converter focuses on the three degree-based formats; UTM support may be added in the future.
How the Conversion Works
Converting between formats is simple arithmetic. Here is how it works using Seoul (37.5665°N) as an example.
DD to DMS
Take the whole number as degrees, multiply the remainder by 60 for minutes, and multiply the new remainder by 60 again for seconds.
degrees = floor(37.5665) = 37°
minutes = floor(0.5665 × 60) = 33'
seconds = (33.99 − 33) × 60 = 59.4"
37.5665° → 37°33'59.4"N
DMS to DD
Divide minutes by 60 and seconds by 3600, then add everything together. Use a negative sign for south or west.
DD = degrees + minutes/60 + seconds/3600
DD = 37 + 33/60 + 59.4/3600
37°33'59.4"N → 37.5665°
Precision Tip
Five decimal places in DD (about 1.1 m) is enough for most uses. Six decimal places gives about 11 cm of precision — more than consumer GPS devices can actually measure.