GPS Coordinate Conversion Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/10/2026
A GPS coordinate in degrees-minutes-seconds format converts to decimal with degrees + minutes ÷ 60 + seconds ÷ 3600, the result being negative for the Southern and Western hemispheres. 45°30'36" North therefore gives 45.51° in decimal.
Explanation
Geographic coordinates can be expressed in two common formats: the sexagesimal degrees-minutes-seconds format (DMS, e.g. 45°30'36" N), inherited from the traditional division of the circle, and the decimal format (e.g. 45.51°), now favored by Google Maps and most modern GPS applications because it is simpler to enter and process computationally. Converting DMS to decimal rests on the same principle as reading a clock: one minute is 1/60 of a degree and one second is 1/3600 of a degree, exactly as a minute of time is 1/60 of an hour — see our angle conversion calculator for the degree unit itself. The sign of the result depends only on the hemisphere: North and East stay positive, while South and West become negative by convention, which lets a single point on the globe be located with a signed pair of numbers (latitude, longitude) rather than four cardinal letters.
Example: 45°30'36" North
Inputs
Degrees: 45. Minutes: 30. Seconds: 36. Hemisphere: North.
Calculation
Decimal = 45 + 30 ÷ 60 + 36 ÷ 3600 = 45 + 0.5 + 0.01 = 45.51.
Result
The coordinate 45°30'36" North corresponds to 45.51° in decimal format.
Frequently asked questions
Why do some older GPS devices or maps still use the DMS format?
The degrees-minutes-seconds format is the direct legacy of the sexagesimal system used since antiquity to divide the circle, and remains widespread in maritime and air navigation, as well as on many printed topographic maps. The decimal format, more recent, took hold with computing and consumer GPS because it avoids manual conversions and integrates more simply into a database or an online map URL.
How do you tell whether a coordinate is a latitude or a longitude?
Latitude (North/South) is always between -90° and 90°, and measures position relative to the equator. Longitude (East/West) is between -180° and 180°, and measures position relative to the Greenwich meridian. A value greater than 90° in absolute terms can therefore only be a longitude.
Does this calculator also convert decimal to DMS?
No, this calculator only handles the DMS-to-decimal direction, the one most often needed (getting a Google Maps-readable coordinate from a map or an old GPS expressed in degrees-minutes-seconds). The reverse direction requires extracting the integer part and successive remainders, a different operation not covered here. To find the local time of a point once its coordinates are known, see our time zone calculator.