Mike Turnbull's WGS-84 World Geodetic System Distance Calculator

This calculator uses Vincenty’s formula, which is extremely accurate and precise on the WGS-84 World Geodetic System (typically to within 0.5mm, or 0.000015"). However, since the Earth is quite bumpy we really don't need that sort of precision in normal practice. This calculator rounds off to practical precisions, depending on the distance involved. You can safely state the precision to be within half of the last significant place. Flexible formats are accepted:

• deg°min'sec with N/S/E/W suffixes (e.g. 24°52'33.5100S, 152°21'8.2728E)
• deg min sec with N/S/E/W suffixes (e.g. 24 52 33.5100S, 152 21 8.2728E)
• deg-min-sec with N/S/E/W suffixes (e.g. 24-52-33.5100S, 152-21-8.2728E). Pretty much any non-numeric seperator character can be used.
• signed decimal degrees, where negative indicates west and south (e.g. 152.352298, -24.875975)

First Geographical Point First Latitude : First Longitude :	Second Geographical Point Second Latitude : Second Longitude :	Units of Distance Select desired unit : Kilometres Metres Miles Yards Nautical Miles Degrees
Azimuth :	Back Azimuth :	Note that the Back Azimuth is NOT the Azimuth minus 180°. This is NOT a mistake. In general, the bearing will vary as you follow a great circle path. The final bearing will differ from the initial bearing by varying degrees according to distance and latitude

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In writing this web page extensive use has been made of Chris Veness' Sperical and Ellipsoidal Javascript. Chris has done a wonderful job of writing the associated Javascript. His coding style is exceptionally neat. I've left Chris' scripts unchanged except for a minor adjustment of calculation precision. I encourage you to visit Chris Veness' Movable Type Ltd. web site. The following statement is made on Chris' web page. I endorse Chris' sentiments.

I offer these formulæ & scripts for free use and adaptation as my contribution to the open-source info-sphere from which I have received so much. You are welcome to re-use these scripts [under a simple attribution license, without any warranty express or implied] provided solely that you retain my copyright notice and a link to this page.