PostSparrow

PHP Code

$lat1 //latitude of first point
$lon1 //longitude of first point 
$lat2 //latitude of second point
$lon2 //longitude of second point 
$unit = K for KM & M for Mile

function point2point_distance($lat1, $lon1, $lat2, $lon2, $unit='K') 
{ 
        $theta = $lon1 - $lon2; 
        $dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) +  cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta)); 
        $dist = acos($dist); 
        $dist = rad2deg($dist); 
        $miles = $dist * 60 * 1.1515;
        $unit = strtoupper($unit);

        if ($unit == "K") 
        {
            return ($miles * 1.609344); 
        } 
        else if ($unit == "M") 
        {
        return ($miles * 0.8684);
        } 
        else 
        {
        return $miles;
      }
    }