Calculating car miles for your carbon footprint is relatively straightforwards using google maps or taking a direct reading from the odometer, however calculating mileage by train is a bit more tricky. If you use the google public transport feature you get the time and route but not distance, and you can’t specify a particular mode of public transport.
So we recommend a great little website called RailMiles Engine by Swlines Ltd at www.mileage.railmiles.org. You can enter the station of origin, destination and also force a particular route with via points.
A good way to test that such a site really calculates the rail route and not the road, is to enter a journey from from Arnside to Grange-over-Sands. By car on google maps it is 14.6 miles, but by train over the viaduct it is only 3 miles.