The Prime Meridian divides the globe into Eastern and Western hemispheres, just as the equator divides the globe into Northern and Southern hemispheres. The Prime Meridian is at 0 degrees longitude, just as the equator is at 0 degrees latitude.

The Prime Meridian
in Greenwich, England
National Maritime Museum

Global address:

Latitude: 51.5°N
Longitude: 0.0°

Special Longitude Clues Coming March 15.
Get Ready! Practice Measuring Time and Distance

Use a time zone map to locate the Prime Meridian and Greenwich, England. Then answer these questions about your location:

• How far east or west of the Prime Meridian do you live (in degrees)?
• What is the time difference (in hours and minutes)?

Facts to Remember

• The Prime Meridian is the reference line you will use for measuring longitude.
• Greenwich, England is the reference point you will use for measuring time.