Latitude and Longitude: Earth's Geographic Coordinate System

Latitude and longitude form a spherical coordinate system pinpointing any location on Earth's surface.

Latitude (Parallels)

• Measures angular distance north/south of the Equator
• Range: 0° (Equator) to 90°N (North Pole) / 90°S (South Pole)
• Lines are parallel circles; length decreases toward poles
• Key parallels: Tropic of Cancer (23.5°N), Tropic of Capricorn (23.5°S), Arctic/Antarctic Circles (66.5°)

Longitude (Meridians)

• Measures angular distance east/west of the Prime Meridian (Greenwich, UK)
• Range: 0° to 180°E / 180°W (meeting at International Date Line)
• Lines are great circles converging at poles; equal length
• Each 15° = 1 time zone hour

Measurement Formats

• Degrees-Minutes-Seconds (DMS): 40° 42' 46" N, 74° 0' 21" W (NYC)
• Decimal Degrees (DD): 40.7128° N, -74.0060° W
• 1° ≈ 111 km (69 mi) at Equator; longitude degree length varies with cosine of latitude

Applications

GPS/GNSS navigation, cartography, geolocation services, astronomy, surveying, aviation/maritime routing, scientific research. Modern smartphones achieve 3–5m accuracy via multi-constellation receivers (GPS, GLONASS, Galileo, BeiDou).

Reference Table