Geographic calculators

This page is designed to help you calculate answers to some common geographical questions and draw maps from simple coordinates. If you have any problems or get unexpected results, please let me know!

Coordinate Converter (D.D, DM.M, DMS)
Calculate the great circle distance between two points
Calculate the great circle distance between two addresses

Draw a direct route between two airports, or multiple airport pairs
Draw range rings around a point
Calculate coordinates at a given bearing and distance

Coordinate Converter

This form will try to read whatever you enter and convert it to three formats: decimal degrees, degrees-minutes, and degrees-minutes-seconds.

Calculate the great circle distance between two points

This calculator will find the distance between two pairs of coordinates to a very high degree of precision (using the thoroughly nasty Vincenty Formula, which accounts for the flattened shape of the earth). The "Draw map" button will show you the two points on a map and draw the great circle route between them.

Calculate the distance between two addresses

This calculator will find the straight-line distance between two locations of any kind: street addresses, city names, ZIP codes, etc. (The coordinates of the locations are provided by the Google Geocoding API.) NOTE: If you just need the coordinates of an address, use the geocoding utilities.

Draw a direct route between airports

This form will simply show you two airports -- represented by a 3-letter IATA code or 4-letter ICAO code -- on a map, along with a line representing the shortest route between them (and the distance, of course).

Draw routes between multiple airports

In the form below, you can enter a list of routes (airport pairs) separated by commas to see all of them, and their distances, on a single map. For example: PDX-MSP,BOS-MIA,ATL-DEN,DEN-PHX

Draw range rings around a point

This form will plot a point on a map -- given a set of coordinates or a "location" (an airport code, ZIP code, city/state pair, street address, or coordinate pair) -- and draw a circle, or circles, around that point. To create multiple rings, separate the values in the "radius" box with commas: e.g., "10mi,50mi,100mi."

To put multiple range rings around different points on a single map, click the "Show coordinates" button and save the resulting text file for each center point, then upload or paste all of the coordinates to GPS Visualizer's map form. "Show coordinates" is also helpful if you want to include range rings in a map with your own GPS files; just upload the range rings coordinates file to the map form along with your other data.

Find the coordinates at a given distance and bearing

This form will tell you what point lies at any distance and bearing from another point. If you don't supply units in the distance box itself (e.g., "100 mi"), it will default to kilometers.

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