mjaschen/phpgeo – простая гео библиотека на PHP

<?php

use Location\\Coordinate;
use Location\\Distance\\Vincenty;

$coordinate1 = new Coordinate(19.820664, -155.468066); // Mauna Kea Summit
$coordinate2 = new Coordinate(20.709722, -156.253333); // Haleakala Summit

echo $coordinate1->getDistance($coordinate2, new Vincenty()); // returns 128130.850 (meters; ?128 kilometers)

https://github.com/mjaschen/phpgeo