Posted on by Paurian

Geocaching Coordinate Distance Calculator

So I’ve come across more than one puzzle cache that goes something like this: you are given a coordinate. The description then tells you to go X feet from the coordinate heading y degrees. How do you calculate the new coordinates?

Examples:
No Latitude
A-Rock-No-Phobia

Well, you perform some trigonometry to identify the longitudinal and latitudinal distances then perform some algebra to convert those distances into coordinates. Something new that I learned is that the distance between each longitudinal degree is different than the distance between each latitudinal degree. Hence you have to use different divisors for each to determine the coordinates.

The calculator still needs to handle situations where the distance hops over a longitudinal or latitudinal degree, but for most puzzles of this type the calculator will work fine. The calculator even handles jumps over degrees, so adding thousands of feet shouldn’t trip it from providing the correct coordinates.

Here’s what to enter:

  • Distance (Feet) = the distance from the center point in feet. If you’re interested in metric entry and results, post a comment.
  • Heading (Compass Degrees) = the heading in compass degrees. 0 degrees is due North, 90 degrees is due East, 180 degrees is due South, and 270 degrees is due West.
  • Latitude of Origin “N” = coordinates in the format “N XX° YYY.ZZZZ'” where XX is the degrees and YYY.ZZZZ is the decimal minutes. This is the common form that Geocaching.com provides for coordinates.
  • Longitude of Origin “W” = the same as the Latitude, only for Longitude. Because it’s frozen as “W”, this calculator will only work for the western hemisphere. Let me know if you’re in the Eastern (or Southern) hemisphere and would like me to update the calculator to accommodate you.

The Calculations are for nerds. The Results are for you. The coordinate results should display a link to Google maps when you’ve entered in all the criteria.

Update: 2017-06-15, I corrected the algorithm. Instead of using the angular distance, it uses a formula based on Haversine distance equation.

Open the Popup Coordinate Distance Calculator

Have fun and post a comment to let me know if it’s useful.

8 Replies to “Geocaching Coordinate Distance Calculator”

  2. Does this still work? I get a Frodbidden on this server error when I try to access the Caculator.

  3. This is a complicated issue, as people who have a high degree of numerical reasoning may struggle during a test if nerves affect their skills, while many are so practiced in using a calculator that they may have forgotten the basics of mental arithmetic.

  4. agility3d – thanks for letting me know. I think my web service provider tightened security to keep down hacking attempts. The calculator has been moved to a different directory to get around this.

  6. I’ve been looking for a calculator that does waypoint projection… and I’m still looking. 🙁 I thought this calc was the answer, but it doesn’t work for me.

    My original waypoint is:

    N 40° 01.612 W 075° 10.660

    I need to project a waypoint 150 feet away at 315° heading. The result from this calc was:

    N 40° 01.615 W 075° 10.665

    That’s only 29 feet away! Whatzup with that?

  7. Hi HBWG – You’re right. I’m not sure exactly why other than perhaps the formulas I used don’t take in account the variance in distance per degree in the latitude when you move up and down the longitude.

    When I get some time I’ll rethink/research the formula and make adjustments. From other comments, it appears that adding a metric system (meters) is in order.

    Thanks for your comments!

  8. It took three years, but I finally got around to fixing the equation! Have fun storming the castle!

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