FAI Distance Calculator

Enter Latitude and longitude of start and finish points and click "compute".
Leg 1 input data
Start Lat. Start Lon.
Finish Lat. Finish Lon.

Distances are in Km and the World model is WGS84. The WGS84 World model became the standard method of calculating distances in microlight and paramotor records on 1 January 2002.
Latitudes and longitudes may be entered in:
DD.DD - Degrees and decimal portions of a degree.
DD:MM.MM - Degrees and minutes and decimal portions of a minute.
DD:MM:SS.SS - Degrees and minutes and seconds and decimal portions of a second.
All distances are rounded up to the nearest metre. No distance is rounded from the pure number more than once so the total distance is correct even though there might appear to be a small discrepancy between it and the sum of the individual leg distances.
Leg percentages are rounded to two decimal places and should be used as a guide only.
Course changes
Should not exceed 145° in closed circuits of three or more legs.
A geodesic
FAI S10 speaks of distances being measured as the 'geodesic' between two points. The WGS84 ellipsoid has an equatorial radius of 6378.1370 Km and a polar radius of 6356.7523 Km. It is centered on the Earth's centre and oriented on its spin axis. The shortest distance between two points on the surface of an ellipsoidal World model is known as a Geodesic which is what this calculator attempts to discover. (A Geodesic is to an ellipsoid what a Great Circle is to a sphere.)
This accumulating calculator is provided courtesy of rmh v 1.2 6 Dec 2006, the javascript is by Ed Williams and course changes by Dave Simpson. It is believed the underlying code used in this calculator is the same as in the 'official' calculator which used to be available from the FAI website but seems to have disappeared, hence the results should be correct, but the results are shown all together which makes it easy to verify a record claim.

Go to the BMAA Records site