Get KM from lat long
public static float getKmFromLatLong(float lat1, float lng1, float lat2, float lng2){
Location loc1 = new Location("");
loc1.setLatitude(lat1);
loc1.setLongitude(lng1);
Location loc2 = new Location("");
loc2.setLatitude(lat2);
loc2.setLongitude(lng2);
float distanceInMeters = loc1.distanceTo(loc2);
return distanceInMeters/1000;
}