What's a cord?
A cord of firewood is 128 cubic feet of closely stacked wood, including the air space between fire logs. The terms "face cord," "rack," "truck load," and "pile" have no agreed meaning or legal meaning. In fact, consumer laws ban the use of these terms in commerce! So, a stack of firewood 4 feet wide, 4 feet tall, and 8 feet long is a cord, as is a stack 2 feet wide, 4 feet high, and 16 feet long. When buying wood, try to deal in terms of real cords or percentages of real cords.
How Much Do I Need?
So, if you just use your fireplace for romance and relaxation, buy a half cord of firewood. If you supplement a heating system with a woodstove or fireplace insert, buy two cords. If you heat exclusively with firewood, you'll need about 4 to 5 cords, depending on the severity of your winters.