How much wood did you actually buy?

A cord is a fixed volume: 128 cubic feet of stacked wood, conventionally 4 ft × 4 ft × 8 ft. A "face cord", "rick" or "rack" is 4 ft × 8 ft by whatever the split length is — which means it is a fraction of a cord that changes with the seller.

The units, once and for all

UnitDimensionsCubic feet
Full cord4 ft × 4 ft × 8 ft128
Face cord, 16 in split4 ft × 8 ft × 16 in≈ 42.7
Face cord, 20 in split4 ft × 8 ft × 20 in≈ 53.3
Face cord, 24 in split4 ft × 8 ft × 24 in64

Sound

A face cord is not a fixed quantity. Three 16-inch face cords make a cord; two 24-inch face cords make a cord. That is the entire mechanism behind most firewood disputes.

How to measure it properly

Stack it first — a dumped pile has enormous air in it and cannot be measured honestly. Then take length along the face, height at the average (not the tallest point), and depth as the split length. Multiply, divide by 128, and you have cords.

If you were quoted a price, put it in and the calculator gives you the effective price per full cord, which is the only figure that compares two sellers.

Volume is only half the purchase

A cord of hickory and a cord of poplar are the same volume and very different amounts of heat. Species matters as much as quantity — see the BTU chart for heat per cord and the seasoning time each species needs.

Watch

Do not move firewood far from where it was cut. Oak wilt and emerald ash borer both travel in firewood — see oak wilt and emerald ash borer.

Sources