Difference Between Parallels and Meridians

The terms Parallels and Meridians are often found in the context of geography and science. The world map we use is marked with countries, continents, and oceans, but have you ever wondered about the different lines that run across the map? These lines, known as parallels and meridians, help us to figure out the exact dimension and direction of a location. Parallels run from east to west and never intersect with each other whereas meridians run from north to south and intersect at the north and south poles. This is the key difference between parallels and meridians.

What are Parallels?

The imaginary lines that run from east to west connecting all locations on a map are known as parallels or latitudes. The five major circles of latitude according to the order on a map from the North Pole to the South Pole are:

  • the Arctic Circle (66° 33′ 38″ N)
  • the Tropic of Cancer (23° 26′ 22″ N)
  • the Equator (0° N)
  • the Tropic of Capricorn (Sagittarius) (23° 26′ 22″ S)
  • the Antarctic Circle (66° 33′ 38″ S)4

These lines of latitude are located parallel to the Equator and never intersect. This is why they are also called parallels.

What are Meridians?

 Meridians or longitudes are also imaginary lines on the Earth’s surface that run up and down from the two poles. These lines of longitude on a map all intersect with each other at the North Pole and the South Pole.

When referring to longitudes, there is a major principle one needs to know. Generally, as we know there are 360 degrees in a circle. The longitude that passes through Greenwich is known as the prime meridian and is allocated the position of 0° longitude. The longitudes of other locations are measured as the angle east or west from the Prime Meridian – +180° eastward and −180° westward.

What is the difference between Parallels and Meridians?

Parallel / Latitude

Meridian / Longitude
  • Parallels are also known as latitudes
  •  Meridians are also known as longitudes
  •  Represented by the Greek letter phi (Φ)
  •  Represented by the Greek letter lambda (λ)
  •  The first parallel is the equator. It is latitude 0.
  •  Greenwich is the prime meridian (0°)
  •  Parallels don’t intersect.
  •  All meridians intersect at two places; the North Pole and the South Pole.
  •  Values range from 0 (the Equator) to 90 (the north and south poles)
  •  Values for longitude range from 0 (the Prime Meridian) to 180 degrees
  •  Letters N and S are used to denote the location
  •  Letters E or W are used to represent  direction
  • Positive values may be used in the Northern hemisphere and negative values in the Southern hemisphere
  • Positive values can be used east of the Prime Meridian and negative values in the west of the Prime Meridian
  •  Every parallel in the same hemisphere has a different length.
  • Every meridian on Earth has the same length.
  •  Every parallel is a full circle
  •  Every meridian is a semi-circle
  •  Each parallel crosses all longitudes
  •  Each meridian crosses all latitudes
  •  To cross all parallels, you have to travel 12,000 miles
  •  To cross all meridians, you have to travel 24,000 miles
  •  Locations with the same latitude do not fall in the same time zone
  •  All locations on the same longitude fall in the same time zone

Major Factors that Need to be Known

  • Each meridian or longitude is perpendicular to all circles of latitudes or parallels at the intersection points.
  • Any specific geographical point can be located by using its longitude and latitude.

For example, if we take the well-known Washington, DC it can be approximately measured and read as 391/2 N. in terms of latitude and 77½ W. in terms of longitudes.

  • We express time using these longitudes and latitudes.

 Image Courtesy:

“Longitude (PSF)” By Pearson Scott Foresman – Archives of Pearson Scott Foresman, donated to the Wikimedia Foundation→This file has been extracted from another file: PSF L-540004.png (Public Domain) via Commons Wikimedia

“Latitude lines” By Latitude_(PSF).png: Pearson Scott Foresman, donated to the Wikimedia Foundationderivative work: Gregors (talk) 08:13, 27 March 2011 (UTC) – Latitude_(PSF).png (Public Domain) via Commons Wikimedia 

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