how to calculate distance between two location on Flutter?(result should be meters)

Question

How to calculate distance between two location in dart?

Answer 1

Without using plugin

  double calculateDistance(lat1, lon1, lat2, lon2){
    var p = 0.017453292519943295;
    var c = cos;
    var a = 0.5 - c((lat2 - lat1) * p)/2 +
        c(lat1 * p) * c(lat2 * p) *
            (1 - c((lon2 - lon1) * p))/2;
    return 12742 * asin(sqrt(a));
  }

result is KM. if you want meter just multiply by 1000. return 1000 * 12742 * asin(sqrt(a))

Answer 2

You can use geolocator plugin to calculate to distances between two coordinates:

An Example:

var _distanceInMeters = await Geolocator().distanceBetween(
   _latitudeForCalculation,
   _longitudeForCalculation,
   _currentPosition.latitude,
   _currentPosition.longitude,
);

Check out GeoLocator Plugin for more info.

Answer 3

Check out latlong. It's a package dedicated to work with coordinates and features sophisticated calculations.

Unlike packages like geolocator it does not come with integrated location services and can be used alongside packages specialized for that.

Answer 4

If you need to check distance between only 2 coordinates, you should use Geolocator().distanceBetween, it is simple, but if you have a list of coordinates maybe you don't want use request for every item, in this case you can use this code to optimize performance:

double calculateDistance(LatLng start, LatLng end) {

  const double earthRadius = 6371.0; // Radius of the Earth in kilometers

  // Convert coordinates to radians
  final double lat1 = start.latitude * (pi / 180.0);
  final double lon1 = start.longitude * (pi / 180.0);
  final double lat2 = end.latitude * (pi / 180.0);
  final double lon2 = end.longitude * (pi / 180.0);

  // Calculate the differences between the coordinates
  final double dLat = lat2 - lat1;
  final double dLon = lon2 - lon1;

  // Apply the Haversine formula
  final double a = sin(dLat / 2) * sin(dLat / 2) +
      cos(lat1) * cos(lat2) * sin(dLon / 2) * sin(dLon / 2);
  final double c = 2 * atan2(sqrt(a), sqrt(1 - a));
  final double distance = earthRadius * c;

  return distance; // Distance in kilometers, add "*1000" to get meters
}

Answer 5

You can use latlong2 which is the continuation of latlong. It has features like distance calculation and path drawing. So you can get distance as path distance as well as direct distance.