This page is designed to help you calculate answers to some common geographic questions and draw maps from simple coordinates. If you have any problems or get unexpected results, please let me know!
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 (great circle) 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.
Draw range rings around a point
This "circle generator" will plot a point on a map -- given a set of coordinates or other location (an airport code, postal code, city/state pair, 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." (If you need to create rings around multiple points simultaneously, you can submit data to the normal map form with a "circle_radius" field added; see the page on triangulation and range rings for more info.)
If you need to put range rings around multiple points on a single map, you can supply your data in the form of a text file or spreadsheet and include a "circle_radius" field; see the example page for more information.
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, along a great circle path. If you don't supply units in the distance box itself (e.g., "100 mi"), it will default to kilometers. (The formula used here was adapted from "Sprong" by Dale Bickel at the FCC.)
(Note: this page used to be entitled "geographic calculators" until Blue Marble threatened to sue GPS Visualizer for the use of that common phrase, which apparently they have trademarked in the capitalized singular.)