Prime rib is one of the most special main courses you can serve at a dinner party, and given that it's such a large cut with a hefty price tag, it's important to consider how much to buy and cook for your guests so you don't make too much nor too little. Follow this simple rule of thumb for figuring out the perfect serving size.

According to Food Network, it's generally safe to buy one pound of prime rib per adult and half a pound per child that you'll be serving. The Kitchn adds that it's a good plan to prepare one bone-in rib for every two guests, but the decision-making doesn't stop there, since prime rib may be sold in two differing cuts.

Butchers typically separate the primal section of ribs into two smaller cuts: the first cut, which is closer to the loin, and the second cut, which is closer to the chuck end of the cow, via America’s Test Kitchen. The first cut is generally more tender, but you may prefer the second cut, since it is fattier and more flavorful.