There is a latlng distanceTo method: http://leafletjs.com/reference.html#latlng
distanceTo( <LatLng> otherLatlng ) Number Returns the distance (in meters) to the given LatLng calculated using the Haversine formula. See description on wikipedia
It calculates the distance (in meters) between two LatLng. However, sometimes I needs to know how many pixels are there between two points. Does anyone have ideas about this?