To calculate the roasting time for the chicken at 375 degrees Fahrenheit, the cooking time is 20 minutes per pound with an additional 10 to 15 minutes. The cooking times vary depending on the temperature of the oven.
A chicken can be roasted for 10 to 15 minutes in a 450 F oven and then the temperature reduced to 375 F to roast the chicken for 20 minutes per pound. This method does not require any additional cooking time added. The high heat roasting method results in a crispier, darker skin.
To determine if the chicken is fully cooked and safe for consumption, a meat thermometer is placed into the inner thigh of the chicken without touching the bone. When the thermometer reads at least 165 F, the chicken is fully roasted. The internal temperature of the chicken continues to rise, even once the bird is taken out of the oven, so if the thermometer reads slightly less than 165 F, it can be pulled out and allowed to rest until the temperature reaches the proper internal temperature. When allowing the chicken to rest, cover it loosely with aluminum foil to redistribute the juices for moister meat.
Using the regular roasting method of 375 F, the typical roasting time for a 5-pound chicken would be 1 hour and 55 minutes, whereas a high heat roasting method using the 450 F setting in the beginning would result in a 1 hour and 40 minute cook time.