The correct way to measure if a turkey is cooked is by using a meat thermometer. This is the only way not to make a mistake and over or under cook your bird. Outside color and crispness does not determine if it’s ready.
While your turkey is roasting in the oven at 325 degrees, be sure to insert the thermometer in multiples places, not touching bone. Once it reaches 165 degrees in the thickest part of the thigh, it is done. If your turkey is stuffed, the center of the stuffing should register at that temperature as well.
In the absence of a thermometer, you can check by cutting into the joint (where the thigh meets the body of the turkey). If the meat close to the bone isn’t pink, it is ready to eat. The juices should also be running clear.
Use this USDA chart to determine cooking times based on turkey size:
After it’s cooked and you take it out of the over, let it rest for at least 25 minutes before carving.