const R = Math.PI / 180; function distance(lat1, lng1, lat2, lng2) { lat1 *= R; lng1 *= R; lat2 *= R; lng2 *= R; return 6371 * Math.acos(Math.cos(lat1) * Math.cos(lat2) * Math.cos(lng2 - lng1) + Math.sin(lat1) * Math.sin(lat2)); } distance(35.666863,139.74954,35.663729,139.744047); // => 0.6063721931946154 distance(43.064313,141.347255,35.663729,139.744047); // => 834.321307653742