Hi Russ, thanks for asking. A cord of 16", loose thrown split wood, (known as "bin volume") will ocupy 180 cubic feet, level full, while 12" wood ocupies 162 cu/ft. This forumula is accurate to 5%+- .
To ensure a full measure to the customer, it may be an idea to buck to 15", this way if the customer insists on 3 face to a cord, he wont be disapointed and will get an extra measure as well.
This I found was the most accurate and fastest way of producing fuelwood. It is hard to cut wood 16" by eye and there may be pieces that vary in length. In these parts we call it summer wood, some are 13", some are 18".
Its fun and profitable to focus on the wood business full time if you have the customer base , the wood and the equip.
John