A full slab of baby back ribs contains between 11 and 13 ribs. The bones are graduated in size and range from 3 inches up to 6 inches.
Baby back ribs are considered the most tender and lean of all the ribs, because they are located close to the pig's loin muscle. Contrary to popular belief, baby back ribs are not the ribs of younger pigs; instead, the name comes from the fact that the ribs are shorter than spareribs. A slab of baby back ribs usually contains anywhere from 1.5 to 2 pounds of meat, with the rest of the slab being comprised of bones.