How long do you cook a 21 lb turkey at 350?

Cooking a large turkey like a 21 pounder can seem daunting, but have no fear! With some simple planning and preparation, you can roast a juicy, flavorful 21 lb turkey in your oven. Here’s a detailed guide on how long you should cook a 21 lb turkey at 350°F to ensure it turns out perfectly moist and delicious.

What Size Roasting Pan Do You Need?

First things first – make sure you have a roasting pan that’s large enough to fit a 21 lb turkey. Here are some roasting pan size guidelines for turkeys:

  • 12-15 lb turkey: use a 16″ x 13″ roasting pan
  • 16-18 lb turkey: use an 18″ x 13″ roasting pan
  • 18-20 lb turkey: use an 18″ x 15″ roasting pan
  • 20-24 lb turkey: use a 20″ x 17″ roasting pan

A 21 lb turkey will likely need at least an 18″ x 15″ roasting pan, but a 20″ x 17″ pan would provide some extra room for good air circulation. Make sure your roasting pan is at least 2-3 inches deep as well.

Calculate Cooking Time for a 21 lb Turkey at 350°F

The general rule of thumb for calculating turkey cooking time is to allow 15-20 minutes per pound at 325-350°F. Here is how you calculate the cooking time for a 21 lb turkey specifically:

  • Preheat your oven to 350°F.
  • Plan for approximately 20 minutes per pound of turkey.
  • For a 21 lb turkey, multiply 21 lbs by 20 minutes per pound = 420 minutes total.
  • Divide 420 minutes total by 60 minutes per hour = 7 hours.

So in summary, cooking a 21 lb turkey at 350°F will take approximately 7 hours in total. This ensures the turkey reaches the safe minimum internal temperature of 165°F needed to kill any harmful bacteria.

Key Tips for Roasting a Juicy 21 lb Turkey

Follow these tips and tricks for roasting a flavorful, tender 21 lb turkey:

  • Thaw frozen turkey safely in the refrigerator 1-2 days before cooking.
  • Remove giblets and neck from turkey cavities; reserve for gravy if desired.
  • Dry turkey inside and out with paper towels; rubbing a little oil on the skin helps browning.
  • Loosely stuff turkey cavity with onion, apple, herbs for extra flavor.
  • Tie/tuck turkey legs together to hold shape during roasting.
  • Place turkey breast side up on a rack in a large roasting pan.
  • Rub turkey skin liberally with softened butter or oil; season with salt, pepper, herbs.
  • Roast turkey uncovered at 350°F, allowing 20 min. per lb (approx. 7 hours for 21 lbs).
  • Baste turkey with pan drippings every hour for moistness and flavor.
  • Check internal temp of stuffing and thickest part of thigh to ensure 165°F.
  • Cover turkey loosely with foil to prevent over-browning if needed.
  • Allow turkey to rest 30 minutes before carving for juicier meat.

Hour-by-Hour Roasting Timeline for a 21 lb Turkey

Here is a detailed timeline of what to expect when roasting your 21 lb turkey at 350°F with our recommended 20 minutes per pound:

Roasting Time Guideline
0:00 – 1:00 hour Turkey is placed in the preheated 350°F oven to start roasting. Skin starts to turn golden brown.
1:00 – 2:00 hours Baste turkey with pan drippings. Thighs and breasts start to brown more. Turkey releases juices into bottom of pan.
2:00 – 3:00 hours Baste turkey again. Check pan juices; add a little water or stock if drying out. Turkey browns evenly.
3:00 – 4:00 hours Continue basting turkey every hour to prevent drying out. Juices run clear when thighs are pierced.
4:00 – 5:00 hours Check internal temp of stuffing and thigh meat. Once 165°F, tent foil over turkey if browning too much.
5:00 – 6:00 hours Thigh and breast meat should register 165°F+ on a meat thermometer when done. Juices run clear.
6:00 – 7:00 hours Turkey should reach safe minimum internal temp of 165°F by 7 hours. Let rest 30 mins before carving.

This timeline can vary slightly depending on your specific oven, so always rely on a food thermometer to gauge doneness rather than time alone. But it provides a helpful estimate of what to expect when roasting a 21 lb turkey at 350°F.

What Internal Temp Should a Turkey Reach?

Using a reliable meat thermometer is crucial for cooking turkey properly. According to USDA Food Safety guidelines, turkey is safe to eat once it reaches a minimum internal temperature of 165°F throughout the meat.

Here are some key internal temperature benchmarks when cooking turkey:

  • 165°F: Minimum safe temperature for dark meat and stuffing.
  • 165°F: Minimum safe temperature for light meat like breasts and wings.
  • 175°F: Temperature for optimal juiciness and tenderness.
  • 185°F: Turkey breast meat starts to dry out.

The best way to determine whether your 21 lb turkey is fully cooked through is to check the temperature in multiple spots, including the innermost part of the thigh or drumstick, the thickest part of the breast, and the center of the stuffing. All should reach 165°F minimum.

Let Turkey Rest Before Carving

Resting your turkey after roasting is a crucial step to ensure tender, juicy meat. The USDA recommends letting turkey rest for at least 30 minutes before carving. This allows time for the juices to be reabsorbed back into the meat fibers.

To rest turkey properly:

  • Transfer turkey from oven to a cutting board or platter.
  • Loosely tent foil or aluminum foil over the top to keep warm.
  • Allow to sit for 30-45 minutes; the internal temp will rise 5-10°F.
  • The meat will reabsorb juices and be easier to carve neatly.

Rushing into carving right away can cause the juices to run out of the meat, making your turkey dry. Be patient – it’s well worth the wait!

Carving Tips for Turkey

Follow these helpful tips for cleanly carving cooked turkey:

  • Use a sharp slicing or carving knife for neat cuts.
  • Remove ties or skewers holding legs together.
  • Slice breast meat on the diagonal into thin or thick slices as desired.
  • Cut along leg joints to remove leg and thigh portions.
  • Slice leg, thigh meat against the grain for tenderness.
  • Keep sliced turkey warm in a 200°F oven if not serving immediately.
  • Pour pan juices into serving gravy; slice any stuffing to serve.

Proper carving makes it much easier to serve cooked turkey neatly. Refer to video tutorials for a visual guide to carving if needed.

Gravy Tips for Turkey

Making gravy is a great way to use the flavorful pan drippings from roasted turkey. Follow these tips:

  • Skim excess fat from turkey pan drippings; reserve if needed.
  • Place roasting pan on stovetop burner over medium heat.
  • Whisk in flour to make a roux; cook 2-3 minutes until golden brown.
  • Gradually whisk in chicken or turkey stock until desired gravy consistency.
  • Add reserved turkey fat or butter if thicker gravy is desired.
  • Season gravy with salt, pepper and any desired herbs.
  • Simmer gravy for 5-10 minutes until nicely thickened.

For a richer flavor, you can add giblets, neck, or other turkey parts to the gravy as it simmers. Strain before serving over sliced turkey. Giblet gravy is a nice traditional option for holiday meals.


Roasting a 21 lb turkey may seem intimidating, but by following the tips above you can have a delicious, perfectly cooked turkey for any occasion. The keys are allowing enough time (about 20 minutes per pound at 350°F), monitoring internal temperatures with a food thermometer, letting the turkey rest before carving, and making flavorful gravy from the pan drippings. With proper planning your Thanksgiving or holiday turkey dinner will be sure to impress!

Leave a Comment