# Travel >> Destinations >> Other Destinations

How to Calculate an Average Longitude

Longitude pertains to a specific location in relation to its position in degrees east or west of the Prime Meridian, which is defined as zero degrees longitude and passes in a north-south direction through the Royal Observatory in Greenwich, a section of London, England. While electronic global positioning devices can automatically determine longitude and latitude, it helps to be able to make these calculations without the aid of electronic devices should an emergency arise in which they are not operational.

Watch
Calculator

Instructions

- 1
  Determine local time and Greenwich Mean Time, or GMT, using a 24-hour clock. For example, if you are in a location within the Pacific Standard Time zone where it is 12 noon, or 12:00 hours, on May 25, GMT will be 20:00 hours, or 8 p.m., on May 25.
- 2
  Subtract the GMT from the local time. In this example, 12 - 20 = -8.
- 3
  Divide the resulting number by 24. In this example, -8/24 = -0.33
- 4
  Multiply the resulting number by 360. In this example, -0.33 x 360 = -119.99. This resultant number represents your average degrees of longitude. A negative number lies to the west of the Prime Meridian and a positive number lies to the east of the Prime Meridian.

What Countries Have the Cheapest Gas?

Characteristics of the Tundra Climate

Other Destinations