How it works
Roasting times here come from the USDA Food Safety and Inspection Service timetable for a whole turkey in a 325°F oven. Each weight range has a span of times because ovens, pans and the bird’s shape vary, so plan around the longer time and start checking at the shorter one.
A stuffed turkey takes longer because the stuffing in the cavity has to reach 165°F too. Many cooks bake the stuffing in a separate dish, which lets the turkey finish sooner and more evenly.
The oven time works backward from when you want to carve and includes a 20-minute rest, which lets the juices settle and makes carving easier. Thawing times follow the USDA rule of about 24 hours in the refrigerator for every 4 to 5 pounds, or 30 minutes per pound in cold water changed every 30 minutes.
Formula
Roasting time: USDA FSIS timetable at 325°F. Refrigerator thaw ≈ weight ÷ 4 to 5 lb per day. Cold-water thaw ≈ 30 minutes per pound.
Questions people ask
How long does it take to cook a 20 lb turkey?
About 4¼ to 4½ hours unstuffed at 325°F, or 4¼ to 4¾ hours stuffed. Check with a thermometer: it is done at 165°F in the thickest part of the breast, the innermost thigh and the wing.
How long does it take to thaw a turkey in the fridge?
About one day for every 4 to 5 pounds. A 16 lb turkey needs 4 days, so for Thanksgiving dinner on Thursday, move it to the fridge by Sunday.
How big a turkey do I need?
Plan on about 1 pound per person, or 1½ pounds if you want leftovers. For 12 guests, that is a 12 lb turkey, or about 18 lb with leftovers.
Can I cook a turkey that is still frozen?
Yes. USDA says it is safe, but it takes at least 50% longer than the times shown here, and you cannot stuff a frozen bird. Remove the giblets once they loosen during cooking.