Turkey calculator: size, thawing, and roasting time

How big a turkey to buy

The US Department of Agriculture's Food Safety and Inspection Service (FSIS) says to allow 1 pound of turkey per person for a fresh or frozen whole turkey, and 1¼ pounds per person for a frozen pre-stuffed turkey. Twelve guests means about a 12-pound turkey; twelve guests with a pre-stuffed bird means about 15 pounds.

If you want leftovers, add the extra pounds yourself in the calculator. FSIS does not set a leftover allowance, so the calculator keeps its rule and shows your extra separately.

How long to thaw a turkey

FSIS lists three safe ways to thaw a turkey: in the refrigerator, in cold water, or in the microwave. In a refrigerator at 40 °F or below, allow about 24 hours for every 4 to 5 pounds. In cold water, allow about 30 minutes per pound, keep the turkey in a leak-proof wrap, change the water every 30 minutes, and cook it as soon as it is thawed.

Microwave thawing depends on the oven, so follow its manual and cook the turkey right away. A frozen pre-stuffed turkey is the exception to all of this: FSIS says not to thaw it, and to cook it from frozen following the package directions.

• 4 to 12 pounds: 1 to 3 days in the refrigerator, or 2 to 6 hours in cold water
• 12 to 16 pounds: 3 to 4 days, or 6 to 8 hours
• 16 to 20 pounds: 4 to 5 days, or 8 to 10 hours
• 20 to 24 pounds: 5 to 6 days, or 10 to 12 hours

How long to cook a turkey at 325 °F

FSIS says to set the oven no lower than 325 °F and gives these approximate times. Stuffing adds time, and FSIS recommends cooking stuffing in a separate dish for more even cooking. Cooking a turkey from frozen is safe, but it takes at least 50 percent longer than a thawed one.

A whole turkey is safe at 165 °F, measured with a food thermometer in the innermost part of the thigh and wing and the thickest part of the breast; stuffing must also reach 165 °F in the center. Let the turkey stand 20 minutes before carving.

• Unstuffed: 8 to 12 pounds 2¾ to 3 hours; 12 to 14 pounds 3 to 3¾ hours; 14 to 18 pounds 3¾ to 4¼ hours; 18 to 20 pounds 4¼ to 4½ hours; 20 to 24 pounds 4½ to 5 hours
• Stuffed: 8 to 12 pounds 3 to 3½ hours; 12 to 14 pounds 3½ to 4 hours; 14 to 18 pounds 4 to 4¼ hours; 18 to 20 pounds 4¼ to 4¾ hours; 20 to 24 pounds 4¾ to 5¼ hours

How the calculator builds the schedule

Enter a dinner time and the calculator works backward: the 20-minute rest, then the longest roasting time in your weight range, then the longest thawing time. Planning on the long end means the turkey is more likely to be ready early than late, and a thawed turkey can wait 1 to 2 days in the refrigerator.

The USDA rows share their edge weights, for example 18 pounds appears in both the 14 to 18 and the 18 to 20 pound rows. On an edge weight the calculator uses the heavier row, which gives the longer time. Weights outside the 4 to 24 pound tables get no estimate; for those, FSIS points to its Meat and Poultry Hotline at 1-888-674-6854.