Home & Cooking
Firewood Cord Calculator
Compute full cords and face cords from a stack, or estimate the cords you need for a heating season. Picks BTU output by wood species and shows total cost.
Firewood details
Stacked firewood
1 full cords
3 face cords (at 16 in splits) over 128 cu ft.
Total BTU
29.1M
BTU per cord
29.1M
Cubic feet
128
Estimated cost
Add price
BTU values reflect oven-dry wood. Burning seasoned wood at 20% moisture or less is what unlocks these numbers. Green wood loses 15-25% of its usable heat boiling off water.
A full cord is the only US legally defined firewood unit: 128 cubic feet of tightly stacked wood, typically 4 ft x 4 ft x 8 ft.
Frequently Asked Questions about the Firewood Cord Calculator
What exactly is a cord of firewood?
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.
What is the difference between a face cord and a full cord?
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.
Which firewood gives the most heat per cord?
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.
How does seasoning affect how much heat firewood gives off?
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.
How many cords do I need to heat my house through winter?
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 to plug in your stove's BTU rating, expected daily burn hours, and the days you actually run it for a tailored estimate.