How long to cook a whole chicken at 225 degrees?

A whole chicken roasted at 225 degrees Fahrenheit will cook for approximately 4-5 hours, depending on the size of the bird. You can check for doneness by inserting a meat thermometer into the thickest part of the thigh, which should read at least 165 degrees Fahrenheit. To ensure even cooking, it is recommended to let the chicken rest for at least 15-20 minutes before carving and serving.