With the crisp days of autumn giving way to frigid winter nights, many of us will be turning to firewood for warmth. But there are some guidelines everyone should know to make sure your wood stacks up. A cord of wood measures four feet high, four feet wide, and eight feet long. A cord also can measure two feet wide, four feet high, and 16 feet long. As long as the stacked wood equals 128 cubic feet, you have a cord of wood. By law, firewood should only be sold by the cord or fraction of a cord. Consumers should avoid purchasing firewood by the truckload, face cord, rack or pile, which are unlawful methods of advertising or selling wood or fuel.