Hi John,

Wow... thanks!! I actually spent two hours in our local library scanning math books. They all described the issue well but NONE offered the formula!

Thanks again,

Ken

>
>Try the following: (In Km)
>
>Convert longitude and latitude to radians: (long or lat * Pi/180)
>theta = lon2 - lon1
>dist = acos(sin(lat1) × sin(lat2) + cos(lat1) × cos(lat2) × cos(theta))
>if (dist < 0)
> dist = dist + pi
>endif
>dist=dist*6371.2