Convert span value into meters on a mapview

Question

Whenever the user zoom in or out the map i need to know how many meters are currently represented on the map (width or height).

What i need is the inverse function o

Answer 1

Here's an easier way (to get width and height in meters)...

- (void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated {

    MKMapRect rect = mapView.visibleMapRect;

    double mapWidth = MKMapRectGetWidth(rect) / 10;
    double mapHeight = MKMapRectGetHeight(rect) / 10;

}