What is Latitude and Longitude

"65 degrees west, 45 degrees north", these words are usually heard in Hollywood action movies for finding enemies/target location. These are Latitude and Longitude co-ordination points of Earth's Geographical points.

In order to input latitude and longitude, you need to know how they are defined.

Latitude is measured from the equator, with positive values going north and negative values going south. Longitude is measured from the Prime Meridian (which is the longitude that runs through Greenwich, England), with positive values going east and negative values going west. So, for example, 65 degrees west longitude, 45 degrees north latitude is -65 degrees longitude, +45 degrees latitude.


How do you convert to Degrees from Degrees:Minutes:Seconds?
The latitude and longitude are input in degrees, so you might need to convert to degrees from degrees:minutes:seconds. There are 60 seconds in 1 minute and 60 minutes in 1 degree. So, for example:

65:45:36 south latitude converts to

           -(65 degrees +
             45 minutes * (1 degree/60 minutes) +
             36 seconds * (1 minute/60 seconds) * (1 degree/60 minutes))

         = -65.76 degrees latitude



So you're looking at a map and you want to know where a city or a place is. And you want to tell someone else. How do you do it?


Let's say you want to tell your friend where Paris is.

Latitude and longitude are two of the most basics terms in all of geography. To understand them, you need to think of Earth as a globe. Further, you need to think of the globe as divided into lots of little sections. Some go east. Some go west. Some go north. Some go south.

So, you know how a circle has 360 degrees? Well, that's true for Earth as well. If you put your finger on the city of Paris and trace all the way around the globe, from right to left, you will trace the full 360 degrees. Go just halfway and you get 180 degrees.

You have just traced 360 degrees of longitude. Longitude is lines that run north and south that measure east or west. The Prime Meridian, in Greenwich, England, is at 0 degrees longitude.

Put your finger on Paris again. Trace around the globe, this time going around the top of the globe, then around the bottom, and back to Paris. You've just traced the full 180 degrees of latitude. Latitude is only 180 degrees. Latitude lines run east and west and measure north or south. The Equator is at 0 degrees latitude.

What does all this give us? Well, you want to tell your friend exactly where Paris is, right? So check out a map that has latitude and longitude marked on it. You'll find that the latitude and longitude markings are every 10 degrees. (Some maps have markings for every 15 degrees or even every 5 degrees.)


See how Paris is almost halfway between 45 degrees and 50 degrees markings? You'll have to estimate here. It's probably about 47.5 degrees. Let's call it 48.

That's latitude. What about longitude? Well, the Prime Meridian is at 0 degrees. That's in England. France is just east of England (for the most part). See how Paris is just less than halfway between the 0 degrees and 5 degrees markings? You'll have to estimate here, too. It's probably about 2 degrees.

So, what is the exact location of Paris? Well, geographers tell us that Paris is indeed at 48 degrees north and 2 degrees east.

Latitude and longitude are big words, but now you know what they mean. Amaze your friends!