how to calculate distance between two coordinates code example

Example 1: calculate distance between two coordinates formula javascript

alert(calcCrow(59.3293371,13.4877472,59.3225525,13.4619422).toFixed(1));



    //This function takes in latitude and longitude of two location and returns the distance between them as the crow flies (in km)
    function calcCrow(lat1, lon1, lat2, lon2) 
    {
      var R = 6371; // km
      var dLat = toRad(lat2-lat1);
      var dLon = toRad(lon2-lon1);
      var lat1 = toRad(lat1);
      var lat2 = toRad(lat2);

      var a = Math.sin(dLat/2) * Math.sin(dLat/2) +
        Math.sin(dLon/2) * Math.sin(dLon/2) * Math.cos(lat1) * Math.cos(lat2); 
      var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)); 
      var d = R * c;
      return d;
    }

    // Converts numeric degrees to radians
    function toRad(Value) 
    {
        return Value * Math.PI / 180;
    }

Example 2: distance between two coordinates latitude longitude formula

function getDistanceFromLatLonInKm(lat1,lon1,lat2,lon2) {
  var R = 6371; // Radius of the earth in km
  var dLat = deg2rad(lat2-lat1);  // deg2rad below
  var dLon = deg2rad(lon2-lon1); 
  var a = 
    Math.sin(dLat/2) * Math.sin(dLat/2) +
    Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * 
    Math.sin(dLon/2) * Math.sin(dLon/2)
    ; 
  var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)); 
  var d = R * c; // Distance in km
  return d;
}
function deg2rad(deg) {
  return deg * (Math.PI/180)
}

Example 3: calculator distance between two coordinates latitude longitude

function distance(lat1, lon1, lat2, lon2, unit) {
        var radlat1 = Math.PI * lat1/180
        var radlat2 = Math.PI * lat2/180
        var theta = lon1-lon2
        var radtheta = Math.PI * theta/180
        var dist = Math.sin(radlat1) * Math.sin(radlat2) + Math.cos(radlat1) * Math.cos(radlat2) * Math.cos(radtheta);
        dist = Math.acos(dist)
        dist = dist * 180/Math.PI
        dist = dist * 60 * 1.1515
        if (unit=="K") { dist = dist * 1.609344 }
        if (unit=="N") { dist = dist * 0.8684 }
        return dist
}