Нашел решение:
var radLat1 = 55 * (Math.PI/180);
var radLon1 = 37 * (Math.PI/180);
var radLat2 = 59 * (Math.PI/180);
var radLon2 = 30 * (Math.PI/180);
var earthRadius = 6372.795;
var radLonDif = radLon2 - radLon1;
var atan2top = Math.sqrt( Math.pow( Math.cos(radLat2) * Math.sin(radLonDif), 2 ) + Math.pow( Math.cos(radLat1)*Math.sin(radLat2) - Math.sin(radLat1) * Math.cos(radLat2) * Math.cos(radLonDif), 2 ) );
var atan2bottom = Math.sin(radLat1)*Math.sin(radLat2)+Math.cos(radLat1)*Math.cos(radLat2)*Math.cos(radLonDif);
var deltaAngle = Math.atan2(atan2top, atan2bottom);
console.log(earthRadius*deltaAngle); /* 614*/