Not an issue but could you could use

[Klinenator]

function distance($lat1, $lon1, $lat2, $lon2, $unit) {

    $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 ($unit == "N") {
        return ($miles * 0.8684);
    } else {
        return substr($miles,0,3);
    }

}

Here is code that will calculate the distance between two distances if you want it.
Nice for seeing how far a place is from you