Decimal degrees are the latitude and longitude geographic coordinates as decimal fractions.
Positive latitudes are north of the equator and less than zero latitudes are south of equator. Positive longitudes are east of the prime meridian and less than zero longitudes are to the west of the prime meridian. Latitude and longitude are usually listed as "Latitude, Longitude", in that order.
Precision
The radius of the semi-major axis (the distance from the center of Earth to the outside at the equator line) of Earth at the equator is 6,378,137.0 meters[1] resulting in a circumference of 40,075,161.2 meters. The number of decimal places required for a particular precision at the equator is:
Degree precision versus length
decimal
places |
decimal
degrees |
DMS |
Object that can be unambiguously recognized at this scale |
N/S or E/W
at equator |
E/W at
23N/S |
E/W at
45N/S |
E/W at
67N/S
|
| 0
|
1.0 |
1° 00′ 0″ |
country or large region |
111.32 km |
102.47 km |
78.71 km |
43.496 km
|
| 1
|
0.1 |
0° 06′ 0″ |
large city or district |
11.132 km |
10.247 km |
7.871 km |
4.3496 km
|
| 2
|
0.01 |
0° 00′ 36″ |
town or village |
1.1132 km |
1.0247 km |
787.1 m |
434.96 m
|
| 3
|
0.001 |
0° 00′ 3.6″ |
neighborhood or street |
111.32 m |
102.47 m |
78.71 m |
43.496 m
|
| 4
|
0.0001 |
0° 00′ 0.36″ |
individual street |
11.132 m |
10.247 m |
7.871 m |
4.3496 m
|
| 5
|
0.00001 |
0° 00′ 0.036″ |
a tree |
1.1132 m |
1.0247 m |
787.1 mm |
434.96 mm
|
| 6
|
0.000001 |
0° 00′ 0.0036″ |
a human |
111.32 mm |
102.47 mm |
78.71 mm |
43.496 mm
|
| 7
|
0.0000001 |
0° 00′ 0.00036″ |
commercial mapping |
11.132 mm |
10.247 mm |
7.871 mm |
4.3496 mm
|
| 8
|
0.00000001 |
0° 00′ 0.000036″ |
specialized mapping |
1.1132 mm |
1.0247 mm |
787.1 µm |
434.96 µm
|
References