View Full Version : Calculating land area for your map?

Brian Leybourne
07-27-2014, 08:41 PM
Hi all,

Is there an easy formula or piece of software which can help determine the area of your map, given a scale? I'm assuming something like campaign cartographer can do it, but I have drawn my map in photoshop, and there's no demo of CC3 so I don't know if there's any way to import a JPG into it other than as a backdrop. Is it possible to import into CC3 and have it recognise at least the basic landmass? Also is there any free software that can do the same thing so I don;t have to buy CC3 just to work out my landmass area? :-)

I have eyeballed it by dividing the (equirectangular) map into 24x12 fifteen degree areas using the awesome g.projector software (also good for showing your rectangle map projected on a sphere), working out what square KM area each square is, and then kind of rtoughly working out hot many squares each landmass basically covers, but it's a crude method and could be well off.

07-27-2014, 09:20 PM

you can ignore most of the first part, but if you want the exact area, you need a equal area projection : Map projection - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Map_projection#Equal-area)
change the projection with gprojector and you should be good to go.

Brian Leybourne
07-27-2014, 09:25 PM
Thanks for the reply, but that will only give me the % land/sea of my entire planet. This is helpful information, but doesn't help me know the size of individual continents.

Hmm, although I guess if I first colored each continent a different color, I could get the percentage for each and use that to calculate the size of each as a fraction of the entire planetary surface area...? Yes, I guess that would work. Thanks!

07-27-2014, 09:44 PM
You can also select them individually with the different selection tools.

and to find how big (km or miles) one area is, you need to decide the size of the planet first. Earth is about 40 000 km in circumference. So say, if your map is 4000 pixel wide at the equator and the same size as Earth, every pixel represent 10km.
If a continent cover an area of 2000 pixels, it's 20 000 km2 (a small continent!).

07-28-2014, 11:20 AM
You can even figure out the area of individual countries/regions this way.
Very useful.