DMS to Decimal Degrees Converter
| Landmark | DMS | Decimal |
|---|---|---|
| Eiffel Tower | 48°51′30″ | 48.8583 |
| Statue of Liberty | 40°41′21″ | 40.6892 |
| Sydney Opera House | -33°51′25″ | -33.8569 |
| Great Pyramid, Giza | 29°58′45″ | 29.9792 |
Maps speak decimal - 48.8584 - while surveyors, sailors and old GPS units speak degrees, minutes and seconds: 48° 51' 30". The bridge is one line of arithmetic: decimal = degrees + minutes ÷ 60 + seconds ÷ 3,600, because each minute is a sixtieth of a degree and each second a sixtieth of that. Enter degrees, minutes and seconds and the decimal lands instantly; paste a decimal coordinate and it unpacks back into DMS.
The sign is the hemisphere: negative degrees mean south latitude or west longitude, and the converter carries the sign through the whole conversion - -33.8568 is Sydney, south of the equator, and entering DMS 33° 51' 24" with the negative box checked lands in the same place. Four decimal places place you within about 11 meters, which is the precision a street address needs; six places is doorway precision.
How to use
- Type degrees, minutes and seconds (0-59 for both small fields) and read the decimal degrees live.
- Or paste a decimal coordinate - negative for south and west - and the DMS fields unpack it.
- Check the table: real landmarks in both formats, with the southern-hemisphere signs shown.
Frequently asked questions
How do I convert degrees minutes seconds to decimal degrees?
Divide the minutes by 60, divide the seconds by 3,600, and add everything to the degrees: 48° 51' 30" becomes 48 + 51/60 + 30/3600 = 48.8583. Both divisions are sixties because the system is Babylonian - a degree splits into 60 minutes, a minute into 60 seconds, exactly like clock time. The converter runs it in both directions live.
What does the negative sign mean in GPS coordinates?
South and west. Latitudes run from +90 at the north pole to -90 at the south pole; longitudes from -180 (west of Greenwich) to +180 (east). So Paris is +48.85, +2.35 while Sydney is -33.86, +151.22 - the signs carry the hemisphere so the numbers stay plain decimals. When converting DMS, apply the sign to the whole coordinate, not to the minutes and seconds separately.
How precise is a decimal degree?
The fourth decimal place is worth about 11 meters - enough for a street address; the fifth is about 1.1 meters, doorway precision; the sixth is 11 centimeters, surveying territory. DMS seconds behave the same way: one second of latitude is about 30 meters. Extra decimals beyond that are decoration, not location - a coordinate with ten decimal places is lying about its accuracy.
Why do GPS units and surveyors still use DMS?
Tradition and division of labor: nautical and aviation charts print DMS grids, property descriptions in deeds quote DMS, and older GPS units default to it. Decimal degrees won the software world because computers and mapping APIs prefer one plain number. Neither is wrong - they are the same angle in two notations, and the converter is the dialect bridge.
Do minutes and seconds here relate to time?
By ancestry only. The degree-minute-second system and clock time share Babylonian base-60 arithmetic - a degree of longitude does correspond to 4 minutes of Earth's rotation - but in coordinates, minutes and seconds are fractions of an angle, not durations. That historical kinship is why both systems count in sixties, and why the confusion between them is eternal.