The turkey has been in the oven for what feels like forever, and while it smells wonderful and looks crisp, golden and ready to eat, you can't tell if it's actually done, just by looking.
What do you do?
Use a thermometer. It's the one foolproof way to check for proper doneness. Pop-up timers aren't always reliable. If you have one, use a digital thermometer with a probe that you can stick into the meat when you first put it in the oven; this allows you to check on the turkey's progress in real time.
How to check: Turkey is done when a thermometer reaches at least 165 degrees. Slide the thermometer into the thickest part of the thigh meat, between the leg and breast; make sure the thermometer does not touch the bone, as this will give an artificially high reading (the bones heat faster than the meat).
(If you're stuffing your turkey before you roast it, you'll need to take the temperature deep in the center of the stuffing, as it came into contact with the raw poultry meat and will also need to cook to a safe temperature of 165 degrees. By the time your stuffing is safe to eat, the breast meat will probably be overcooked and dry. It's best to cook them separately.)
How long does a turkey take to cook? While temperature is the most reliable indicator of doneness, it helps to have a rough timetable when you're planning. According to the USDA, for an unstuffed turkey roasting at 325 degrees, you should allow 2¾ to 3 hours for an 8- to 12-pound turkey; 3 to 3¾ hours for a 12- to 14-pounder; 3¾ to 4¼ hours for a 14- to 18-pounder; 4¼ to 4½ hours for an 18- to 20-pounder and 4½ to 5 hours for an 20- to 24-pounder.
For a stuffed turkey, allow 3 to 3½ hours for an 8- to 12-pound turkey; 3½ to 4 hours for a 12- to 14-pounder; 4 to 4¼ hours for a 14- to 18-pounder; 4¼ to 4¾ hours for an 18- to 20-pounder; and 4¾ to 5¼ hours for a 20- to 24-pounder.
There are other ways to tell if the turkey is done, though they are not as reliable as a thermometer. Gently twist the thigh joint; if it moves up and down easily and the hip joint gives without effort, your turkey might be done. Also, insert the carving fork or knife into the thickest part of the thigh meat; if the juices run clear and aren't pink, the turkey is probably done.
Still, invest in a thermometer. It's the best way to safely check for doneness. By the way, these tips are not only good for turkey; they'll work with chicken and other poultry.