Calculate the geographical distance (in meters) between 2 points with extreme accuracy.
This library implements Vincenty's solution to the inverse geodetic problem. It is based on the WGS 84 reference ellipsoid and is accurate to within 1 mm (!) or better.
This formula is widely used in geographic information systems (GIS) and is much more accurate than methods for computing the great-circle distance (which assume a spherical Earth).
Include the gem in your Gemfile:
gem 'vincenty_distance'
or
$ gem install vincenty_distance
and
require 'vincenty'
require 'vincenty'
boston = { latitude: 42.3541165, longitude: -71.0693514 }
newyork = { latitude: 40.7791472, longitude: -73.9680804 }
distance = Vincenty.distance_between_points(boston, newyork)
# distance = 298_396.057 m
Wikipedia: Vincenty's formulae