How to Calculate a Cord of Wood From Any Woodpile Size
By The Calcumatix Team Reviewed by Calcumatix Editorial Review 3 min read
Quick Answer
Calculate a cord of wood by multiplying the stack length, height, and depth in feet, then dividing the cubic volume by 128. A stack measuring 8 feet long, 4 feet high, and 4 feet deep has 8 × 4 × 4 = 128 cubic feet, which equals one full cord.
A cord measures the stacked volume of firewood, including the wood and the small air gaps between pieces. The calculation starts with three stack measurements: length, height, and depth. Multiply those dimensions in feet to get cubic feet, then divide by 128.
How Do You Calculate a Cord of Wood Step by Step?
A firewood stack equals one cord when the measured stacked volume reaches 128 cubic feet. The National Conference on Weights and Measures firewood guidelines define a cord as 128 cubic feet of compactly stacked wood. Use the firewood calculator to quickly convert measurements.
Follow these steps to calculate cords of wood:
- Stack the firewood in straight, compact rows.
- Measure the total stack length in feet.
- Measure the average stack height in feet.
- Measure the stack depth, which usually matches log length.
- Convert any inches to feet by dividing by 12.
- Multiply length × height × depth to find cubic feet.
- Divide the cubic feet by 128 to find full cords.
Use a firm measuring tape and keep it level across the stack. Take several height readings if the top row is uneven, and use the mean height.
What Formula Converts a Woodpile Into Full Cords?
The cord formula converts a three-dimensional stack into a fraction or multiple of 128 cubic feet:
- Stacked Volume (cu ft) = Length (ft) × Height (ft) × Depth (ft)
- Number of Cords = Stacked Volume (cu ft) ÷ 128
When depth is measured in inches, convert to feet first:
- Depth (ft) = Depth (in) ÷ 12
For example, a 16-inch log depth becomes 16 ÷ 12 = 1.3333 feet. Keep extra decimal places during intermediate steps to prevent rounding errors.
How Does the Formula Work on a 12 Foot Stack?
Suppose you have a stack measuring 12 feet long, 4 feet high, and made of 16-inch logs:
- Convert Depth to Feet: 16 in ÷ 12 = 1.3333 ft.
- Calculate Stacked Volume: 12 ft × 4 ft × 1.3333 ft = 63.9984 cu ft.
- Calculate Cords: 63.9984 cu ft ÷ 128 cu ft/cord = 0.49998 cord.
The stack contains 0.50 cord (half a cord), rounded to two decimal places.
How Is a Face Cord Different From a Full Cord?
A full cord has a fixed stacked volume of 128 cubic feet. A face cord describes a single row measuring 4 feet high by 8 feet long, but its depth varies with log length. NIST consumer guidance notes that terms like face cord, rack, or pile lack a single legal volume definition without specifying log length.
| Measurement | Typical Dimensions | Stacked Volume | Full Cord Share |
|---|---|---|---|
| Full cord | 4 ft × 4 ft × 8 ft | 128 cu ft | 1.00 cord |
| Face cord (16 in logs) | 4 ft × 8 ft × 1.333 ft | 42.67 cu ft | 0.33 cord |
| Face cord (20 in logs) | 4 ft × 8 ft × 1.667 ft | 53.33 cu ft | 0.42 cord |
| Face cord (24 in logs) | 4 ft × 8 ft × 2 ft | 64.00 cu ft | 0.50 cord |
What Measuring Mistakes Change the Cord Result?
The largest errors come from measuring a loose pile as though it were compactly stacked. Measure neat rectangular rows rather than mound peaks or loose truck beds. When measuring multiple uneven rows, compute each row separately and add their volumes.
Entering depth in inches without converting to feet makes the result 12 times too large. Always convert inches to feet before multiplying.
For more building and materials calculation tools, visit the construction calculators hub.
Sources and Standards
Frequently asked questions
What dimensions make one full cord of firewood?
One full cord occupies 128 cubic feet of compactly stacked firewood. Standard dimensions are 4 ft high × 4 ft deep × 8 ft long, but any shape totaling 128 cu ft (such as 2 ft × 4 ft × 16 ft) equals one cord.
How many cubic feet are in half a cord of wood?
Half a cord contains 64 cubic feet of neatly stacked firewood (128 cu ft × 0.5 = 64 cu ft).
Does a face cord always equal one third of a cord?
A face cord equals roughly one-third of a full cord only when using 16-inch logs (4 ft × 8 ft × 1.333 ft = 42.67 cu ft). Longer or shorter logs change the face cord volume.
Can a pickup truck hold a full cord of firewood?
Rarely in one load. A full cord requires 128 cubic feet of stacked space, which exceeds most standard pickup bed capacities and payload weight limits.