Major Parallels of Latitude
Arctic Circle
Located at 66 degrees, 30 minutes north latitude, the Arctic Circle marks the line of demarcation between the northern frigid zone, or north polar region, and the northern temperate zone.
Arctic Circle (absolute location: 66° 33′ 44″ N)
Tropic of Cancer
Located at 23 degrees, 27 minutes north latitude, the Tropic of Cancer marks the northern limit of the earth’s tropical--or torrid--zone.
Tropic of Cancer (absolute location: 23° 26′ 16″ N)
Equator
Located at zero degrees latitude, the equator represents the imaginary line around the earth--or parallel of latitude--that lies an equal distance from both the geographic north and south poles. It serves to divide the earth into two hemispheres: the southern and northern.
Equator (absolute location: 0° latitude)
Tropic of Capricorn
Located at 23 degrees, 27 minutes south latitude, the Tropic of Capricorn marks the southern limit of the earth’s tropical--or torrid--zone.
Tropic of Capricorn (absolute location: 23° 26′ 16″ S)
Antarctic Circle
Located at 66 degrees, 30 minutes south latitude, the Antarctic Circle marks the line of demarcation between the southern frigid zone, or south polar region, and the southern temperate zone.
Antarctic Circle (absolute location: 66° 33′ 44″ S)
Major Meridians of Longitude
Prime Meridian
The meridian of 0 degrees longitude which runs through the original site of the
Royal Observatory at Greenwich, England, and from which other longitudes are reckoned
Prime Meridian (absolute location: 0°)
International Date Line
The meridian of 180 degrees longitude, the regions to the east of which are counted as being one day earlier in their calendar dates than the regions to the west.
International Date Line (absolute location: 180° longitude)

0
15 °
30 °
45 °
60
°
75 °
90 °
Length of 1 Degree of Latitude
If the Earth were perfectly spherical in shape, the length of one degree of latitude would constant everywhere on the Earth's surface. However, because of the slight flattening of the Earth at the poles, the length of one degree of latitude varies slightly with distance from the Equator, but averages approximately 111 km.
At Latitude Length of 1 Degree of Latitude
0° - 1°
68.70314861 mi (110.567 km)
39
° - 40°
89
° - 90°
68.98649388 mi (111.023 km)
69.4065408 mi (111.699 km)
Average 68.9722 mi (111 km)
Length of 1 Degree of Longitude
Since meridians of longitude converge at the poles, the length of one degree of longitude varies from approximately 111 km at the Equator to 0 km at the poles. At any latitude, the length of 1 degree of longitude can be calculated by multiplying the length of 1 degree of longitude at the Equator times the cosine of the latitude.
At Latitude Length of 1 Degree of Longitude
69.17166249 mi (111.321 km)
66.83033584 mi (107.553 km)
59.9300087 mi (96.448 km)
48.9944971 mi (78.849 km)
34.6737553 mi (55.802 km)
17.9594916 mi (28.903 km
0 km