The USDA Food Safety and Inspection Service publishes recommended roasting times for whole turkey based on weight. These times assume a 325°F conventional oven, a thawed bird, and no stuffing in the cavity. The calculator uses those weight-based ranges as a baseline, then adjusts upward for stuffed birds (add 30-45 min) and slightly downward for 350°F (subtract approximately 15-20 min).
Time estimates are a range, not a fixed number. A 15 lb turkey at 325°F shows 3 hr 45 min to 4 hr 15 min. Variables that affect where you land in that range include oven calibration accuracy, whether the bird was fully thawed, altitude, the type of roasting pan, and whether you used a roasting bag or cover. Build planning around the maximum, not the minimum. A turkey finished early can rest safely for up to 2 hours under foil, but a turkey running late creates real timing problems.
If you are scaling a stuffing recipe or side dishes to match your bird size, use our recipe conversion calculator to scale ingredient amounts up or down to match your serving count.
The USDA minimum safe internal temperature for all poultry is 165°F measured in the thickest part of the thigh, away from the bone. The timer is only an estimate; the thermometer reading is the only reliable indicator that the turkey is safe to eat. Oven temperatures vary by ±25°F on most home ovens, and a bird that was not fully thawed will consistently run behind the estimated time.
Many experienced cooks pull the turkey from the oven at 160°F in the thigh and immediately tent it with foil. Carryover cooking, the continued rise in internal temperature after heat is removed, brings the thigh from 160°F to 165°F during the resting period. This technique reduces the risk of an overcooked, dry breast, which reaches 165°F earlier than the thigh and can become dry if the bird stays in the oven until the thigh hits 165°F exactly.
Rest time is not optional for a quality result. A 15-20 lb turkey should rest 45-60 minutes under loose foil. Juices that migrate to the surface during cooking redistribute back into the meat during rest. Carving immediately after the oven produces a plate full of juice and noticeably drier meat than carving after a full rest. Once you know your serving count, use our recipe cost calculator to estimate total ingredient cost for the full meal.