A full prime rib/standing rib roast is seven (7) ribs, close to 15 pounds, and enough to feed a crowd of 14 or more people (depending on how big of eaters they are). The term “standing” means the bones are included in the roast, thus the roast can stand by itself. A rib roast comprises of seven ribs starting from the shoulder (chuck) down the back to the loin.
For a generous serving of roast, figure on two people per rib. That means if you plan to serve:
- six (6) people – three (3) rib roast
- eight (8) people – four (4) rib roast
- ten (10) people – five (5) rib roast
- twelve (12) people – six (6) rib roast
- fourteen (14) people – seven (7) rib roast
Don’t even bother with less than a three-rib roast, any less than that is not a roast but rather a thick steak and would be better treated as such.