The question is straightforward, but there are so many variables that make answering this a moot point. Not only is every turkey a different size (duh), but ovens vary drastically—heck, even the cook times of turkeys that weigh the same can vastly differ due to breed, fat content, breast size, etc. Did you brine it? Stuff it? Truss it? OK, then add a few more minutes to that!
The truth is, no matter how fancy-shmancy a turkey cooking time chart looks, you'll only really know when your bird is cooked through if you check its internal temperature with an instant-read thermometer.
"For turkey that is moist and juicy," writes J. Kenji López-Alt at Serious Eats, "aim for breasts that register 150°F in their deepest section and legs that register at least 165°F."
I like to roast my unstuffed, room-temperature turkey at 350°F—and if you must know for how long, it's about 13 minutes per pound. That means, say, a 12-pound turkey should take about 2 1/2 hours to cook.
Guess who agrees? Nigella Lawson. Her turkey cook times in the seminal classic, Nigella Christmas, line up with my numbers above (and no one's cooked as many turkeys as she has).
"The cook times here always seem shockingly short to other people," Lawson writes, "but the truth is we've all been overcooking turkeys for years, and then complaining about how dull and sawdusty they are. If your turkey starts at room temperature, and is untrussed and without stuffing, and your oven thermostat is working correctly, these cooking times hold."
I've read horrifying accounts on other sites advising 20 minutes per pound (!). I can just taste the sawdust.
Again, go by internal temperature if you can (150°F at the breast and 165°F at the leg). I personally like to pull my bird out of the oven about 5°F earlier because it will continue to cook as it rests—and you must let your turkey rest before carving it, lest all the juices come rushing out onto the cutting board.
Eric Kim is the Senior Editor and Table for One columnist at Food52. Formerly the Digital Manager at Food Network, he writes about food, travel, and culture and lives in a tiny shoebox in Manhattan with his dog, Quentin "Q" Compson. His favorite writers are William Faulkner, John Steinbeck, and Ernest Hemingway. You can follow him on Twitter @ericjoonho.