An 18-pound turkey roasts 4¼–4½ hours at 325°F unstuffed or 4¼–4¾ hours stuffed; done when the turkey reaches 165°F in the thickest parts.
Holiday dinner hangs on two things: steady oven heat and an accurate thermometer. This guide gives you reliable times for an 18-pound bird, explains what moves those times up or down, and shows simple checks so the meat stays juicy and safe.
Cook Time For 18 Pound Turkey: The Snapshot
Set the oven to 325°F. For a fresh or fully thawed whole turkey that weighs around eighteen pounds, plan about four and a quarter to four and a half hours if it’s unstuffed. If you load stuffing inside the cavity, the range stretches to about four and a quarter to four and three-quarter hours. Time is a guide; doneness is 165°F in the breast, thigh, and any stuffing. For planning, you can compare your weight range to the turkey roasting chart from FoodSafety.gov.
| Weight Range | Unstuffed Time | Stuffed Time |
|---|---|---|
| 8–12 lb | 2¾–3 hr | 3–3½ hr |
| 12–14 lb | 3–3¾ hr | 3½–4 hr |
| 14–18 lb | 3¾–4¼ hr | 4–4¼ hr |
| 18–20 lb | 4¼–4½ hr | 4¼–4¾ hr |
| 20–24 lb | 4½–5 hr | 4¾–5¼ hr |
| Whole Breast 6–8 lb | 2¼–3¼ hr | 3–3½ hr |
| Half Breast 2–3 lb | 50–60 min | — |
These ranges assume a roasting pan with a rack, the bird on the center rack of the oven, and a turkey that started fully thawed. The only true finish line is temperature: all turkey parts need to register 165°F. The USDA safe temperature chart sets that line for poultry.
Why Times Vary For An Eighteen-Pound Turkey
Stuffing Inside The Bird
Stuffing slows heat through the cavity. If you choose to stuff, pack it loosely and check that the center of the stuffing also reaches 165°F. A tight pack adds time and dries the breast.
Oven Accuracy And Pan Setup
Many ovens run hot or cool. A cheap oven thermometer can reveal a gap. A dark, non-stick pan cooks a bit faster than a shiny one. A deep, crowded pan blocks air and stretches time. Keep the turkey on a rack so hot air flows around it.
Bird Temperature At The Start
A turkey that’s still cold in the core will lag. Fully thaw in the refrigerator (about 24 hours per 4–5 lb) or in cold water (about 30 minutes per lb, changing water often). If you start partly frozen, expect up to 50% more time.
Oven Open Time
Every long peek dumps heat. Group your basting and checks. If you like the skin extra bronzed, you can turn the pan once midway and leave the door shut the rest of the time.
Temperature Rules That Keep Turkey Safe
Poultry is safe at 165°F. Place your probe in the deepest breast, the inner thigh near (not on) the bone, and the thickest drum. If stuffed, probe the middle of the stuffing too. Readings should reach 165°F in all those spots. For best texture, pull the bird when the breast hits about 160°F and the thigh 170°F; carryover during the 20–30 minute rest will nudge the breast to 165°F.
Set the oven to 325°F, aim for 165°F in the thickest parts, and rest before carving. That sequence keeps texture and safety in line.
Simple Plan For An 18-Pound Turkey
Prep
- Thaw fully. Pat dry. Remove giblets. Tuck the wing tips under.
- Season under and over the skin. Light oil or softened butter helps browning.
- Set the oven to 325°F with the rack in the lower third.
- Choose unstuffed for the most even result. If you prefer stuffing inside, keep it loose.
Roast
- Place the turkey on a rack in a shallow pan. Add a cup of water or stock to catch drips.
- Roast breast-side up. Start checking temps around the 4-hour mark.
- Tent with foil near the end if the skin darkens too fast.
Rest And Carve
- When the breast reads 165°F at the deepest point, move the turkey to a board.
- Rest 20–30 minutes to settle juices. Then carve, starting with the legs and thighs.
18 Lb Turkey Cook Time In Convection Ovens
A convection fan moves hot air faster, so surfaces brown sooner and total time often drops. Keep the oven at 325°F but begin temperature checks 30–40 minutes earlier than a standard oven. The safest way to manage cook time for 18 pound turkey in a convection setting is still by thermometer, not by minutes alone.
Spatchcock, Grill, And Other Routes
Butterflying (spatchcocking) flattens the bird, exposing more skin and speeding heat to the breast. Many cooks see the breast hit 160–165°F near the four-hour mark even with a large bird, though pan depth, racks, and airflow change results. Lidded grill setups can work too; plan roughly 15–18 minutes per pound with the lid closed and steady heat, and keep the probe in place the whole way. FSIS outlines several alternate routes for whole birds.
Why A Chart Is Only A Starting Point
Charts are handy for planning and shopping. Exact timing still depends on starting temperature, pan depth, rack position, and how often the door opens. Pair the chart with a reliable probe and you’ll land on tender meat without guesswork.
Time Planning Backward From Dinner
Hosting gets easier when you work backward. This planner locks in the cook time for 18 pound turkey so sides and gravy line up. Use this planner for an 18-pound bird roasted unstuffed at 325°F. Adjust the roast window if you know your oven runs slow or if you choose stuffed.
| Clock Time | Task | Notes |
|---|---|---|
| 12:45 PM | Preheat & prep pan | Rack in lower third; shallow pan with rack |
| 1:00 PM | Bird in oven | Start at 325°F |
| 5:00 PM | Start temp checks | Spot-check breast and thigh |
| 5:15–5:45 PM | Finish roast | Target 4¼–4½ hours total |
| 5:45–6:15 PM | Rest | Carryover to 165°F in breast |
| 6:15 PM | Carve & serve | Slice across the grain |
| By 8:15 PM | Chill leftovers | Refrigerate within 2 hours |
Thawing Rules That Protect Cook Time
A full thaw keeps roasting predictable. Plan one day in the fridge for every four to five pounds, so an 18-pounder needs about four days. For a same-day save, use the cold-water method: submerge in cold water and change the water every 30 minutes, allowing about 30 minutes per pound. Once thawed in water, roast right away.
Quick Flavor Tips Without Changing Timing Much
- Dry brine: Salt the turkey 24–48 hours ahead. Better seasoning, minimal effect on time.
- Compound butter: Slide under the skin for browning and moisture.
- Broth in the pan: Keeps drippings from scorching and adds gravy depth.
Safe Handling After The Meal
Move sliced turkey and stuffing to shallow containers and chill within two hours. Reheat leftovers to 165°F before serving. This keeps texture and safety in line.
Core Takeaways You Can Trust
- Cook time window: For eighteen pounds, expect 4¼–4½ hours unstuffed at 325°F; stuffed can reach 4¾ hours.
- Finish by temperature: Use 165°F as the finish line in the breast, thigh, and any stuffing.
- Plan the rest: Rest 20–30 minutes so juices settle and temps level.
