Firewood Cord Calculator (volume and BTU)
Turn a woodpile's measurements into cords, and see how much heat it holds by species.
How much wood is in my pile?
Volume and share of a full cord for common stack sizes (4 ft high × 8 ft long), by piece length. See the full BTU per cord chart for heat by species.
| Stack | Cubic feet | Share of a full cord |
|---|---|---|
| 4 × 8 ft, 12-inch pieces | 32.0 | 0.25 |
| 4 × 8 ft, 16-inch pieces | 42.7 | 0.333 |
| 4 × 8 ft, 18-inch pieces | 48.0 | 0.375 |
| 4 × 8 ft, 24-inch pieces | 64.0 | 0.5 |
| 4 × 8 ft, 4 ft deep (full cord) | 128 | 1 |
Worked example
A neat stack 8 ft long, 4 ft high and 4 ft deep is 128 cubic feet, exactly one cord. The same 8 × 4 ft face made of 16-inch pieces is 42.7 cubic feet, a third of a cord. In white oak (29.1 million Btu per cord, USU Table 1) that third of a cord holds about 9.7 million Btu.
How it works
A cord is 128 cubic feet of wood stacked tightly, with the pieces parallel and touching. NIST/NCWM notes that a 'face cord' isn't a legal unit of sale, so ask for the volume in cords. Heat per cord is for air-dried wood and changes widely by species: Osage-orange holds about twice as much as cottonwood.
Questions
How many cubic feet is a cord of wood?
128 cubic feet, such as a stack 4 ft high, 4 ft deep and 8 ft long.
What is a face cord?
A stack 4 ft high and 8 ft long, as deep as the pieces are long. With 12 to 18 inch pieces that's 32 to 48 cubic feet (USU). NIST/NCWM says it isn't a legal unit of sale.
How much wood fits in a pickup?
USU Extension says a full-size pickup with a standard bed holds about half a cord (64 cu ft) when loaded level with the top of the bed.
Sources
Guides
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