Flight Indira Gandhi International Airport departs from Delhi Indira Gandhi International Airport at 08:45 and arrives at Kolkata Netaji Subhas Chandra Bose International Airport at 11:00.
The flighttime is about 2h 15m. The distance travelled ("as the bird flies"): 1262 Km. So the average speed is roughly 561 Km.
The best month to arrive at Delhi is August and the most expensive month to fly is April. (Average prices, based on 556 datapoints.)
We have a lot more statistics for flights 6E 513 and between Delhi and Kolkata.