Understand Latitude and Longitude

Geographers use an invisible grid drawn on the Earth to describe the exact location of any place on the planet. This grid is made up of two sets of lines: lines of latitude and lines of longitude. Together they create a coordinate system that works like a giant address for every point on Earth.

Lines of Latitude

• Latitude lines run east to west (horizontally) around the Earth — they are also called parallels because they never meet.
• Latitude measures how far north or south a location is from the equator.
• The equator is the most important line of latitude — it sits at 0° and divides Earth into the Northern and Southern hemispheres.
• Latitude values range from 0° at the equator to 90°N at the North Pole and 90°S at the South Pole.
• Examples: New York is at about 41°N; Sydney is at about 34°S.

Lines of Longitude

• Longitude lines run north to south (vertically) from pole to pole — they are also called meridians.
• Longitude measures how far east or west a location is from the prime meridian.
• The prime meridian is the most important line of longitude — it sits at 0° and passes through Greenwich, England.
• Longitude values range from 0° at the prime meridian to 180° east or west.
• The prime meridian divides Earth into the Eastern and Western hemispheres.

How Coordinates Work

• A coordinate is written as latitude first, then longitude — for example: 51°N, 0°W is Greenwich, England.
• Degrees (°) measure how far a location is from the reference line (equator or prime meridian).
• The letters N, S, E, W tell us the direction from the reference line.
• To find a place: first find the latitude (how far north/south), then the longitude (how far east/west).
• Example: London is approximately 51°N, 0°W; Cairo is approximately 30°N, 31°E.