Get distance from 2 locations (Lat/Long)?

I've searched the web for a formula to calculate the distance from 2 points with latitude/longitude:

ACos(Sin(value( "lat1" ))*Sin(value( "lat2" ))+Cos(value( "lat1" ))*Cos(value( "lat2" ))*Cos(value( "long2" )-value( "long1" )))*6371.0

(6371 is the earth radius in km) from here: http://www.movable-type.co.uk/scripts/latlong.html and here: http://itouchmap.com/latlong.html


but the distance dont work for me (in my case should be under 10km, the formula shows me something like 278)

what I'm doing wrong here?!?

thanks for your help!

Richie

Here is some functions I have used for this calc in the past that are very accurate:

http://www.galcho.com/Blog/default.aspx?date=2007-05-17

You should be able to convert the T-SQL or C# function easily.

Does the Expression Editor Support a radians function?!?

SOLUTION!!:

(ACos(Sin(value( "lat1" ))*Sin(value( "lat2" ))+Cos(value( "lat1" ))*Cos(value( "lat2" ))*Cos(value( "long2" )-value( "long1" )))*6371.0)/180*3.141592654

(what i have missed was the conversation to radiant)

*Bookmarks this thread* Always such a complicated equation, easier to refer here when needed XD