According to the weight :
Small (3-5kg/6-11lb) : Thaw in refrigerator in its packaging. Preheat the oven to 160°C (325°F). Roast in covered roasting pan for 2.5 to 3 hours for an unstuffed turkey or 3-3.5 hours for a stuffed turkey.
Medium (5-7kg/11-16lb) : Thaw in refrigerator in its packaging. Preheat the oven to 160°C (325°F). Roast in covered roasting pan for 3.5 to 3.75 hours for an unstuffed turkey or 4-4.25 hours for a stuffed turkey.
Large (7-9kg/16-20lb) : Thaw in refrigerator in its packaging. Preheat the oven to 160°C (325°F). Roast in covered roasting pan for 4.5 to 5.5 hours for an unstuffed turkey or 5 to 6 hours for a stuffed turkey.
Oven temperatures may vary. These instructions are provided as guidelines only.
Keep refrigerated or frozen. Do not refreeze if thawed.
For more information, read our article on How to cook a turkey in the oven.