Cord of Wood Calculator
Easily determine the volume of your stacked firewood in cords. Enter the dimensions of your woodpile below to calculate a cord of wood.
Calculate Your Cord of Wood
Total Stack Volume: N/A cubic feet
Standard Cord Volume: 128 cubic feet
Fraction of a Cord: N/A
Volume Comparison
Chart comparing your stack’s volume to a standard cord (128 cu ft).
Common Firewood Stack Dimensions & Cord Equivalents
| Length (ft) | Width (ft) | Height (ft) | Volume (cu ft) | Cords |
|---|---|---|---|---|
| 8 | 4 | 4 | 128 | 1.0 |
| 4 | 4 | 4 | 64 | 0.5 |
| 8 | 4 | 2 | 64 | 0.5 |
| 8 | 2 | 4 | 64 | 0.5 |
| 12 | 4 | 4 | 192 | 1.5 |
| 8 | 4 | 6 | 192 | 1.5 |
| 16 | 4 | 4 | 256 | 2.0 |
Table showing the volume and cord equivalent for common firewood stack sizes.
What is a Cord of Wood?
A cord of wood is a standard unit of measure for firewood and pulpwood in the United States and Canada. It represents a neatly stacked pile of wood occupying a volume of 128 cubic feet. The dimensions of a standard cord are most commonly visualized as a stack 8 feet long, 4 feet wide, and 4 feet high (8 ft × 4 ft × 4 ft = 128 cu ft).
Anyone buying or selling firewood, or managing wood resources, should understand what a cord of wood is to ensure fair transactions and proper volume estimation. The term refers to the total space the stacked wood occupies, including the wood itself and the air spaces between the pieces. A “full cord” or “bush cord” always refers to this 128 cubic foot volume.
Common misconceptions include confusing a cord of wood with a “face cord,” “rick,” or “pickup truck load,” which are smaller, non-standardized units and typically represent less volume than a full cord. A face cord, for example, is usually a stack 8 feet long and 4 feet high, but only as wide as the length of the firewood pieces (e.g., 12, 16, or 24 inches), making it significantly less than 128 cubic feet.
Cord of Wood Formula and Mathematical Explanation
The calculation for a cord of wood is based on the volume of the stacked wood pile.
1. Calculate the Volume of the Stack: Measure the length (L), width (W), and height (H) of the stacked wood, preferably in feet. The volume is then:
Volume = Length × Width × Height (cubic feet)
2. Calculate the Number of Cords: Since one standard cord of wood is 128 cubic feet, divide the total volume of your stack by 128:
Number of Cords = Total Volume / 128
For example, if you have a stack that is 8 feet long, 4 feet wide, and 4 feet high:
Volume = 8 ft × 4 ft × 4 ft = 128 cubic feet
Number of Cords = 128 / 128 = 1 cord
Variables Table:
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| L | Length of the wood stack | feet (ft) | 2 – 50+ ft |
| W | Width of the wood stack (or log length) | feet (ft) | 1 – 8 ft (often 4 ft) |
| H | Height of the wood stack | feet (ft) | 2 – 8 ft (often 4 ft) |
| Volume | Total cubic volume of the stack | cubic feet (cu ft) | 16 – 1000+ cu ft |
| Cords | Number of cords | cords | 0.1 – 10+ |
Practical Examples (Real-World Use Cases)
Example 1: Standard Stack
You have stacked firewood against a wall. The stack measures 16 feet long, is 4 feet deep (the length of the logs), and is stacked 4 feet high.
- Length = 16 ft
- Width = 4 ft
- Height = 4 ft
Volume = 16 × 4 × 4 = 256 cubic feet
Number of Cords = 256 / 128 = 2 cords
You have 2 full cords of wood.
Example 2: Irregular Stack Averaging
You have a pile of wood that is roughly 10 feet long and 4 feet wide, but the height varies. You take several height measurements (e.g., 3 ft, 3.5 ft, 4 ft, 3.5 ft) and find the average height to be about 3.5 feet.
- Length = 10 ft
- Width = 4 ft
- Average Height = 3.5 ft
Volume = 10 × 4 × 3.5 = 140 cubic feet
Number of Cords = 140 / 128 ≈ 1.09 cords
You have just over one cord of wood.
How to Use This Cord of Wood Calculator
1. Measure Your Stack: Use a tape measure to find the length, width (depth), and average height of your neatly stacked firewood pile in feet. For irregular heights, take measurements at several points and average them.
2. Enter Dimensions: Input the measured length, width, and height into the respective fields in the calculator.
3. View Results: The calculator instantly shows the total volume of your stack in cubic feet and, most importantly, the equivalent number of cords. It also shows the fraction of a cord if it’s not a whole number.
4. Interpret Results: The “Number of Cords” is the key result. If you are buying or selling, this number tells you the volume based on the standard 128 cubic feet per cord of wood. The chart visualizes how your stack compares to a full cord.
Key Factors That Affect Cord of Wood Measurement
While the volume calculation is straightforward (L x W x H), several factors influence how much solid wood you actually get in a cord of wood:
- Stacking Tightness: A tightly stacked pile with minimal air space will contain more solid wood within the 128 cubic foot volume than a loosely thrown pile. Always aim for or expect neatly and tightly stacked wood when measuring a cord of wood.
- Piece Length and Straightness: Short, straight, uniform pieces stack more tightly and have less air space than long, crooked, or irregularly shaped pieces.
- Splitting: Split wood generally stacks more tightly than round logs because flat surfaces can fit together better.
- Wood Diameter: A cord made of many small-diameter pieces will have more air space than one made of fewer large-diameter pieces, assuming both are stacked well.
- Settling: Wood can settle after stacking, reducing the height and overall volume slightly over time.
- Measurement Accuracy: Ensuring you measure the average height and the full length and width accurately is crucial. For uneven stacks, take multiple height measurements.
Understanding these factors helps when you buy firewood or are assessing your own supply.
Frequently Asked Questions (FAQ)
1. What is the difference between a cord and a face cord?
A full cord of wood is 128 cubic feet (e.g., 4’x4’x8′). A face cord is also typically 4 feet high and 8 feet long, but its width is only the length of the firewood pieces (e.g., 12″, 16″, or 24″). So, a face cord of 16″ wood is 1/3 of a full cord (16″ is 1/3 of 48″ or 4 ft).
2. How much does a cord of wood weigh?
The weight varies greatly depending on the wood species (density) and moisture content (seasoning). A cord of green, dense hardwood like oak can weigh over 5,000 lbs, while a cord of dry, lighter wood like pine might weigh 2,000-3,000 lbs. Our firewood BTU chart also gives some weight indications.
3. How long will a cord of wood last?
This depends on your heating needs, stove efficiency, wood type, and climate. For someone using wood as a primary heat source in a cold climate, a cord might last 4-8 weeks. For occasional fires, it could last a whole season or more.
4. What is a “rick” of wood?
A “rick” is another non-standard term, often used interchangeably with “face cord.” Its volume depends on the length of the pieces.
5. How much space do I need to store a cord of wood?
You need a space that can accommodate a stack of 128 cubic feet, ideally with good air circulation. A common footprint is 8 feet long by 4 feet deep, stacked 4 feet high.
6. Should I buy wood by the cord or by weight?
Buying by the cord of wood (volume) is generally fairer, especially if the wood is seasoned, as weight is heavily influenced by moisture. If buying green wood by weight, be aware you are paying for a lot of water. Check local regulations, as some areas mandate sales by volume.
7. How do I measure a pile that isn’t neatly stacked?
It’s very difficult to accurately estimate the volume of a loose pile. It’s best to stack it first, or if buying, ask for it to be stacked for measurement or buy from a reputable dealer who sells measured cords.
8. Does the type of wood affect the cord measurement?
No, a cord of wood is a measure of volume (128 cubic feet), regardless of wood type. However, the amount of heat (BTU content) and weight per cord will vary significantly between different types of firewood.