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how long do you cook an 18 lb turkey

For an 18 lb turkey roasted at 325°F, plan on about 4 to 4½ hours if it’s unstuffed, and 4¼ to 4¾ hours if it’s stuffed, but always go by temperature, not time.

Core timing guidelines

  • For an 18 lb unstuffed turkey at 325°F, most safety and cooking charts give a range of 4 hours to about 4½ hours.
  • For an 18 lb stuffed turkey , the range is usually 4¼ to 4¾ hours at 325°F.
  • A common rule of thumb is 15–20 minutes per pound for an unstuffed bird at 325°F, which puts 18 lb roughly in that 4–6 hour window, with reputable charts clustering around 4–4½ hours.

Safe internal temperatures

  • The turkey is done when the thickest part of the thigh reaches 170–175°F , and the breast reaches 165°F.
  • If the turkey is stuffed , the center of the stuffing also needs to reach 165°F ; if the meat is done but stuffing is cooler, scoop it out and finish it in the microwave or oven separately.

Simple step-by-step timeline

  1. Preheat oven to 325°F.
  1. Prepare turkey (pat dry, season, stuff only if you must; many modern guides recommend cooking stuffing separately for food safety).
  1. Roast breast-side up on a rack in a roasting pan:
    • Start checking temperature around 3¾–4 hours so you do not overshoot.
  1. Rest the turkey, loosely tented with foil, for 20–30 minutes before carving so the juices redistribute.

Little “forum-style” reality check

“My 18-pounder hit temp right at the 4-hour mark, so I’m glad I started checking early instead of trusting the chart.”

  • Actual cooks often report that turkeys can cook faster or slower than charts suggest, depending on oven calibration, how cold the bird is, and whether the roasting pan is crowded.
  • Treat time charts as a guide , but let your thermometer be the final judge every time.

Quick Scoop (SEO-style notes)

  • If you are searching “how long do you cook an 18 lb turkey ,” most up-to-date guides in 2024–2025 agree on about 4–4½ hours at 325°F unstuffed , and 4¼–4¾ hours stuffed , with doneness confirmed at 165–175°F internal.

Information gathered from public forums or data available on the internet and portrayed here.