CADGISHow to use the converter
- Choose the format you already have: DD, DMS or DDM.
- Select Latitude or Longitude.
- Enter the value. For DMS and DDM, pick N/S or E/W. For DD, use a minus sign or a letter (
-74.006or74.006 W). - Results in all three formats update as you type. Adjust the decimals, then press Copy results.
The three coordinate formats
DD, DMS and DDM describe exactly the same position. They only write the angle differently.
Decimal Degrees (DD)
A single signed number, e.g. -33.868800. North and East are positive, South and West are negative. It's the standard for GIS software, web maps, spreadsheets and databases.
Degrees Minutes Seconds (DMS)
Degrees, whole minutes and seconds, with a hemisphere letter: 33° 52' 07.68" S. It's traditional on topographic maps, survey plans and legal descriptions.
Degrees Decimal Minutes (DDM)
Degrees plus minutes with a decimal part, and no seconds: 33° 52.1280' S. It's common on handheld and marine GPS units, in aviation, and in geocaching.
Conversion formulas
DD = Degrees + Minutes / 60 + Seconds / 3600
DD = Degrees + Decimal minutes / 60
Decimal minutes = Minutes + Seconds / 60
To go from DD, take the whole degrees and multiply the remaining fraction by 60 to get minutes. For DMS, multiply the fraction of the minutes by 60 again to get seconds. Make the value negative, or use S/W, for the southern and western hemispheres. The tool rounds only the displayed values and carries correctly, so you never see 60 minutes or 60 seconds.
Examples
| Location | DD | DMS | DDM |
|---|---|---|---|
| Sydney lat | -33.868800 | 33° 52' 07.68" S | 33° 52.1280' S |
| Sydney lon | 151.209300 | 151° 12' 33.48" E | 151° 12.5580' E |
| New York lat | 40.712800 | 40° 42' 46.08" N | 40° 42.7680' N |
| New York lon | -74.006000 | 74° 00' 21.60" W | 74° 00.3600' W |
Example: DDM to DD
51° 30.444' N → 51 + 30.444 / 60 = 51.507400
Example: DMS to DDM
40° 42' 46.08" N → minutes = 42 + 46.08 / 60 = 42.768 → 40° 42.7680' N
Frequently asked questions
What is the difference between DMS and DDM?
Both start with whole degrees. DMS splits the rest into whole minutes and seconds. DDM keeps the minutes as a decimal and has no seconds.
Which format should I use for Google Maps or GIS software?
Decimal degrees work best. Enter them as latitude, longitude, e.g. -33.8688, 151.2093. Most GIS software expects DD with at least 6 decimals.
Why does my GPS show a different format?
Many GPS receivers default to DDM. Use this converter to switch it to DD for GIS or to DMS for a survey plan.
Does converting the format change the datum?
No. Only the way the number is written changes. The datum (for example WGS84) stays the same.