For eight people, a practical approach is to aim for about 1.25 to 1.5 pounds of raw turkey per person. That generally yields enough meat for servings plus some leftovers, while keeping cook times reasonable. How to size it

• If you want leftovers: choose a turkey around 10 to 12 pounds (uncooked, unstuffed). This tends to yield comfortable portions with some extra for sandwiches or pot pies.
• If you’re serving mostly adults with hearty appetites and want minimal leftovers: a 8 to 9 pound turkey can work for eight people, though you’ll have less room for seconds and potential bits for future meals.

Practical tips

• Consider bone and skin: the raw weight includes bones and skin, so plan portions accordingly. A rough guide is about 0.8 to 0.9 pounds of usable meat per person from a whole turkey, depending on the bird’s size and how it’s portioned.
• Roasting efficiency: smaller birds roast more quickly and evenly; very large birds can be trickier to cook through without overcooking the outer layers.
• If you prefer fewer leftovers and want a simpler plan, you can also split the crowd by cooking two smaller birds (e.g., two 4–5 pound turkeys) instead of one large one; this shortens cook times and provides more even results.

If you’d like, share any constraints (oven size, preferred leftover amount, whether you’ll have stuffing, or if you’ll also serve other main proteins) and a more tailored recommendation can be provided.