Firewood Cord Calculator

A full cord is the only firewood unit defined by US weights and measures law. It is a tightly stacked volume of 128 cubic feet, classically 4 ft wide by 4 ft tall by 8 ft long. Any other term you hear (rick, rank, face cord, stove cord, pile, truckload) is regional slang with no legal definition, so always confirm dimensions or cubic feet before paying for delivery.

A face cord is one stack 4 ft tall by 8 ft long with a depth equal to the length of one split, typically 16 in. That works out to about 1/3 of a full cord (128 cu ft) at standard 16 in splits. Buy three face cords of 16 in wood and you have a full cord. Buy a face cord of 24 in splits and you actually get half a full cord, so the split length matters.

Dense hardwoods top the table. Oven-dry white oak hits about 29.1 million BTU per cord, red oak and hard maple about 24 million, birch around 20.8 million, and softwoods drop to roughly 17 million for pine. A cord of oak puts out roughly 30 percent more usable heat than a cord of pine, which is why hardwood usually commands a premium even when the volume is identical.

Fresh-cut (green) wood can be 50 percent water by weight. A wood stove has to boil all that off before the wood ignites cleanly, which steals 15-25 percent of the usable BTU and produces creosote in the chimney. Seasoned firewood at 20 percent moisture content or less burns hot and clean, delivers close to the full published BTU per cord, and is the EPA's recommendation for any wood stove.

A modern wood stove as the primary heat source in a moderate US climate typically burns 3-5 full cords of hardwood per season. Tighter, well-insulated homes lean toward the lower end; drafty older homes or harsh northern winters can push past 6 cords. Use the heating-need mode with the stove's output rating, efficiency, daily burn hours, and season length for a tailored estimate.