how calculate km distance using lat & long

Question

I want km distance sing latitude and longitude in c#...

Madan Shekar · Answer

public static double DistanceTo(double lat1, double lon1, double lat2, double lon2, char unit = 'K') { double rlat1 = Math.PI*lat1/180; double rlat2 = Math.PI*lat2/180; double theta = lon1 - lon2; double rtheta = Math.PI*theta/180; double dist = Math.Sin(rlat1)*Math.Sin(rlat2) + Math.Cos(rlat1)* Math.Cos(rlat2)*Math.Cos(rtheta); dist = Math.Acos(dist); dist = dist*180/Math.PI; dist = dist*60*1.1515; switch (unit) { case 'K': //Kilometers -> default return dist*1.609344; case 'N': //Nautical Miles return dist*0.8684; case 'M': //Miles return dist; } return dist; } If it helps mark as answer.

Amit Gupta · Answer

https://stackoverflow.com/questions/6366408/calculating-distance-between-two-latitude-and-longitude-geocoordinates

Željko Perić · Answer

Hello, here is another version of distance calculation : double Calculate_Distance( double long1, double long2, double lat1, double lat2) { // Result in Km double distance = 0; // Earth radius const double R = 6372.795477598; // Radians double rad = Math.PI / 180; double long1 *= rad; double long2 *= rad; double lat1 *= rad; double lat2 *= rad; distance = R * Math.Acos ( Math.Sin(lat1) * Math.Sin(lat2) + Math.Cos(lat1) * Math.Cos(lat2) * Math.Cos(lon1- lon2) ); return distance; } All the best, Željko Peric

Kalyani Shevale · Answer

how to calculate using google api key?????