Question: how long does it take to cook a whole chicken on 400 degrees?
Answer: Roast the chickens at 400 degrees for about an hour and a half, depending on the size of the birds. The way I figure time for this is to take the average weight of one of the chickens (say, 4.5 lbs) and calculate 20 minutes per pound (that would be 90 minutes for a 4.5 lb chicken).