How do i find the exact middle piont between calgary alberta canada and st louis MO?

Question

i need a more exact point than what using crude tools like rulers and pencils would find. i need to find the long. lat co-ordinates if at all possible

Answer 1

Although I think Ezar's suggestion would be the most accurate on any good map from today, you don't want "crude" measuring methods.

So let's examine your statement. You want the EXACT middle point between Calgary, AB and St. Louis, MO. To do that you would need the EXACT starting and ending coordinates for the two cities. Are you starting and ending in the exact center of each town, or starting from your house to a friend's house? That would alter the coordinates slightly and result in an incorrect EXACT middle point.

So here is what I did and I think it is pretty accurate. I found a website that listed the two cities coordinates:

Calgary, AB      51 1N      114 1W

St. Louis, MO    38 35N      90 12W

The degrees would be easy to subtract and calculate in this case if we did not include the minutes.

51 - 38 = 13

114 - 90 = 24

But you want EXACT so let's add the minutes to this. Remember that those must be done in Base 60.

1 minute - 35 minutes = -34 minutes

1 minute - 12 minutes = -11 minutes

So I take my degrees and remove that to come up with:

13 - 34 minutes = 12 and 26 minutes

24 - 11 minutes = 23 and 49 minutes

That should be the distance in degrees and minutes between the two longtitude and latitude coordinates for the cities. So if I add HALF that amount to St. Louis (or subtract half from Calgary) I get the following set of coordinates:

44 48N     102 7W

With that, I end up somewhere in South Dakota. More specifically, just off West Brushy Creek Road, south of Faith, SD and west of Route 73.

I then used a map, piece of string, measured to the two cities and halved it, and it was pretty darn accurate!

Answer 2

google maps

Answer 3

draw a straight line connecting them.

Measure the line.

divide by 2.

Mark That distance on map.

Answer 4

Find one of those maps that shows Calgary or St. Louis as if it were the north pole and measure the distance then find the halfway point.

It would take a lot of math to do it with co-ordinates.  Look in books about navigation for details.  It involve stuff called spherical trigonometry.