So I am trying to figure out the square miles of my homebrew game world map but I drew it on hex paper and now I'm not sure how many square miles it is. I did a search online to find a conversion but all I could really find was an old forum thread that offered up a bunch of mathematical formulae for determining the area of a hex and debate to their accuracy for game purposes with no real answer.
Can anyone here help a brother out? If I can get an answer than hopefully other folks wandering about the interwebs with just such a problem will be able to find an answer as well.
What I am looking for is a simple means of calculating hex miles to square miles. If I have x number of hexes, each y number of miles across, my map is z number of square miles. That sort of thing, but a formulae that isn't too complicated and involving figuring the area based on the length of the sides and so on and so on geometry. Something the non mathies will be able to do. If a website with a calculator or such exsits that would be great too.
The map I made for my homebrew world is 1,178 hexes large with each hex representing 20 miles. How many square miles is my map?
Geometry to the rescue!
If your hexes are 6 miles from edge to edge (a 3-mile inner radius), then each hexagon has an area of approximately 31.2 square miles. From corner to corner, through the center of the hex, the distance is about 6.9 miles (this is the outer radius of the hexagon).
1178 hexes times 31.2 square miles = 36753.6 square miles. A little bit bigger than Indiana.
If your hexes are 1 inch (map distance) from edge to edge, then 1 inch equals 6 miles on your map. Just ignore the hexes and measure distances with a ruler, then convert them to miles!
For example, if the area you want to measure is 8 inches by 3 inches, you have 24 square inches. One square inch = 36 square miles, and 24 * 36 = 864 square miles.
Yay geometry!
I cross posted this to another forum and got a great link for folks who don't like to deal with calulations and such. Hexagon Measurment Calculator
My map measures hexes the way I assume most folks measure hexes and thats from one edge to the opposite edge or from the center of one hex to the center of an adjacent hex, which is the same. For the linked site that is h or height. Click the buttom and it gives the area of the hex, then multiply that by the number of hexes on your map and huzzah, square miles! So the same thing you said. :D
To use my above example, my map is 1,178 hexes (38 wide and 31 tall). Each 20 miles across, so my map is just over 408,071.1 square miles, or about three Californias. So, bigger than I intended but its a costal region and has a fair amount of ocean and islands so not too huge.
That's a huge area to adventure in 
intently wrote:
20 miles is a really big hex.
6 miles is traditional, or 24 miles for zoomed-out maps.
What's a good size for a hex crawl campaign? I'm thinking of a "New World" type event with a newly discovered continent.
Kahless wrote:
Okay, that's good to know. Never done or played a hexcrawl, but it seems interesting to me and I was wanting to see if I could put something together from the vague ideas floating around in my head. Just wanted some numbers on what to start with. Thanks!
ankiyavon wrote:
Kahless wrote:
Six mile hexes are great for hex crawls because it is feasible for a party to explore a six mile hex in a single day. Hex crawls are about exploration and discovery so maintaining a feasible scale for promoting that activity is pretty good. You can also zoom in on the map for certain areas, such as around towns, with a one mile hex.