If you start roasting a 14-pound turkey at 375 degrees at 7 a.m. and need to feed 15 people by 1 p.m., how many pounds of cranberries do you need if the stuffing is baked outside the bird and the pumpkin pie is cut into 11.75 equal wedges?

Or am I the only cook who suffers flashbacks to grade school word problems when I try to calculate the many mathematical angles of assembling Thanksgiving dinner?

Fear not. I took one for the turkey team and did the math for you, sorting out all the numbers you need. And because this is Thanksgiving, all serving estimates are generous to allow for seconds and leftovers.

Choosing

For turkeys less than 16 pounds, estimate 1 pound per serving. For larger birds, a bit less is fine as they have a higher meat-to-bone ratio. If your goal is to have very ample leftovers, aim for 1 1/2 pounds per person no matter how big the turkey: for eight people, a 12-pound turkey; for 10, a 15-pounder, etc. If you have the oven space, two smaller birds are more manageable than one huge one.

Thawing

The safest way to thaw a frozen turkey is in the refrigerator. You’ll need about 24 hours per 4 to 5 pounds of turkey. For speedier thawing, put the turkey in a sink of cold water. Change the water every 30 minutes, and plan for about 30 minutes per pound.

Roasting

Roasting temperatures vary widely by recipe. However you roast, use an instant thermometer inserted at the innermost part of the thigh (without touching bone) to determine doneness. The meat needs to hit 165 degrees for safe eating. If the skin gets too dark before the center reaches the proper temperature, tent the turkey with foil.

The following roasting time estimates are based on a stuffed turkey cooked at 325 degrees: 12-pound turkey, 3 to 4 hours; 15-pounder, 4 to 4 1/2 hours; 18-pounder, 4 1/2 to 5 hours.

For unstuffed, estimate total roasting times at 15 minutes per pound. And remember, a crowded oven cooks more slowly, so plan ahead if your bird needs to share the space.

Basting

Basting the bird with its juices helps crisp the skin and flavor the meat. Do it every 30 minutes, but no more. Opening the oven door frequently lets heat escape and can significantly slow the cooking.

Resting

Like most meat, turkey needs to rest before serving for the juices to redistribute. Cover it with foil and a few bath towels layered over that to keep it warm, and let it rest for 20 to 30 minutes.

On the side

•  Carrots: a 1-pound bag makes 4 to 5 servings.

•  Cranberry sauce: a 12-ounce package of fresh cranberries makes about 2 1/4 cups of sauce; a 16-ounce can has 6 servings.

•  Gravy: plan for 1/3 cup per person.

•  Green beans: 1 1/2 pounds makes 6 to 8 servings.

•  Mashed potatoes: a 5-pound bag makes 10 to 12 servings.

•  Stuffing: a 14-ounce bag makes 10 to 12 servings.

Leftovers

To minimize the chance of food-borne illness, leftovers should be cleared and refrigerated within two hours of serving. Once refrigerated, they should be consumed within three to four days, and can be frozen for three to four months, after which they will begin to lose quality.