I'm trying to compare prices for bone-in vs boneless beef rib roasts (aka standing rib roast aka prime rib aka ribeye roast). What is the weight of the bones as a percent of the total pre-cooked weight? Without this number it's impossible to compare prices. (Please no debate about which is better - save that for another thread.)
The key factor is going to be the breed of cattle. Angus, a very high quality beef, also has heavy bone structure and a less favorable bone-to-meat ratio, where as limousine has a lighter bone structure with more meat-to-bone. Other breeds will vary as well, with hereford being (IMHO) the 'happy medium'. But, of course, each individual steer is going fall with a range of possible values rather than a constant factor.
Such value propositions really come down to individual taste and priorities. I suggest to that the comparison is really not just a xLb of bone-in vs. yLb of bone-out. The quality of getting bone-in (again, IMHO)is far superior. The attached rack provides for a degree of insulation and allows for a slower roast protecting the whole rack from over-cooking (a sin to be sure).
If you are stuck on just 'doing the math' if you are looking at a whole (7 bone) prime rib, the rack, the bones, along with the meat & fat attached to the bone that would remain if the rack were to be removed, will account for about 15% of the overall weight (give-or-take all of the variables mentioned - and more). For something 'more or less' than the whole prime (ribs 6-12) as you can see the bones will vary in size depending on whether you are at the short end or the large end of the rack.
This article, from Weber, offers a good deal of analysis of the rib roast in general and may provide some good additional information for you.
Bone-In vs. Boneless
Beef rib roasts are sold two ways—bone-in or boneless. There are several advantages to cooking a bone-in beef rib roast:
- Fat and connective tissue that surround the bones add moisture and flavor to the meat as it breaks down during cooking.
- Rich flavor from bone marrow may migrate into the meat during cooking.
- Bones slow the cooking of meat and limit the evaporation of moisture.
- Bones are easily removed after cooking and make a tasty treat for the chef!
Buy a bone-in beef rib roast whenever you can.