The journey from Barrackpore to Dehradun covers 1500 kilometers. The most practical way is to take a train from Howrah station. The route passes through major cities like Delhi. Expect a travel time of 26 to 30 hours by train. Flight is also an option from Kolkata airport to Dehradun airport.
Total Distance: 1500 km by road, 1300 km straight-line.
The Doon Express is a good option.
October to March for pleasant weather.